Answer:
Step-by-step explanation:
(a)
From the given information; we can compute the null and the alternative hypothesis as follows:
[tex]H_o : \mu = 38[/tex]
[tex]H_1 : \mu < 38[/tex]
Level of significance ∝ = 1% = 0.01
The critical values of t distribution since the sample size n = 20 is:
n - 1
= 20 - 1
= 19 degree of freedom
Assuming the population is normally distributed:
The t test can be computed by using the EXCEL FUNCTION
= TINV(0.01, 19 )
= 2.539483
[tex]t_{0.01,19} = 2.539483[/tex]
However;
we were also given the sample mean X to be = 35 minutes
the standard deviation SD = 5 minutes
Thus; the test statistics can be computed as;
[tex]t = \dfrac{\bar X - \mu}{\dfrac{s}{\sqrt{n}}}[/tex]
[tex]t = \dfrac{35- 38}{\dfrac{5}{\sqrt{20}}}[/tex]
[tex]t = \dfrac{-3}{\dfrac{5}{4.472}}[/tex]
[tex]t_o = -2.6833[/tex]
The P-value P ( t < [tex]t_o[/tex]) = P( t < - 2.633)
= 0.007355
P-value [tex]\approx[/tex] 0.0074
Decision Rule: If P - value is less than the level of significance; we are to reject the null hypothesis.
Conclusion: P-value < level of significance ; i.e 0.0074 < 0.01; so we reject the null hypothesis and accept the alternative hypothesis.
Thus; we conclude that the average time for assembling the computer board is less than 38 minutes at 0.01 level of significance.
b).
Given that:
Sample size n = 20
level of significance = 0.05
The population variance σ² is more than 22
Thus null hypothesis and the alternative hypothesis can be computed as follows:
[tex]H_0 : \sigma^2 = 22[/tex]
[tex]H_1 : \sigma^2 < 22[/tex]
From above;
degree of freedom df = 19
The critical value of [tex]X^2[/tex] at df = 19 and ∝ = 0.05 is = 30.14353 at the right tailed region.
[tex]X^2_{0.05,19} =[/tex] 30.14353
The test statistics [tex]X^2[/tex] for the sample variance is computed as:
[tex]X^2= \dfrac{(n-1 )s^2}{\sigma^2}[/tex]
[tex]X^2= \dfrac{(20-1 )25}{22}[/tex]
[tex]X^2= \dfrac{(19)25}{22}[/tex]
[tex]X^2= \dfrac{475}{22}[/tex]
[tex]X^2[/tex] = 21.5909
The P-value for the test statistics is :
= 1 - P( [tex]X^2[/tex] < 21.5909)
= 1 - 0.694914
= 0.305086
The P-value = 0.305086
Decision Rule: If P - value is less than the level of significance; we are to reject the null hypothesis.
Conclusion: SInce the P-value is greater than the level of significance ; i.e
0.305086 > 0.05 ; Therefore; we do not reject the null hypothesis.
Therefore the data does not have sufficient information to conclude that the population variance is more than 22 at 5% level of significance.
I hope that helps a lot.
The temperature is −18.2 Celsius in South Dakota and -9.7 Celsius Minnesota. Which one of the following inequalities correctly compares the temperatures? Choose 1 answer: Which one of the following descriptions is correct?
Answer:
The answer is A) -9.7 > -18.2
Step-by-step explanation:
This is because, when you are thinking about negative numbers, the closer they are to 0, the greater they are. So, it is warmer in Minnesota.
Answer:
A and A
Step-by-step explanation:
A restaurant chain is measuring the levels of arsenic in chicken from its suppliers. The question is whether there is evidence that the mean level of arsenic is greater than 80 ppb, so we are testing vs , where represents the average level of arsenic in all chicken from a certain supplier. It takes money and time to test for arsenic so samples are often small. A sample of chickens from one supplier is tested, and the resulting sample mean is . Subtracting 11 from the sample data to move the mean down to the null mean of results in the following data: .
57, 64, 70, 82, 84, 123
Use StatKey or other technology to create the randomization distribution for this test. Find the p-value.
Answer:
The p-value of the test is 0.1515.
Step-by-step explanation:
The hypothesis for the test can be defined as follows:
H₀: The mean level of arsenic is 80 ppb, i.e. μ = 80.
Hₐ: The mean level of arsenic is greater than 80 ppb, i.e. μ > 80.
As the population standard deviation is not known we will use a t-test for single mean.
It is provided that the sample mean was, [tex]\bar X=91[/tex].
The adjusted sample provided is:
S = {57, 64, 70, 82, 84, 123}
Compute the sample standard deviation as follows:
[tex]\bar x=\farc{57+64+70+82+84+123}{6}=80\\\\s=\sqrt{\frac{1}{6-1}\times [(57-80)^{2}+(64-80)^{2}+(70-80)^{2}+...+(123-80)^{2}]}=23.47[/tex]
Compute the test statistic value as follows:
[tex]t=\frac{\bar X-\mu}{\s/\sqrt{n}}=\frac{91-80}{23.47/\sqrt{6}}=1.148[/tex]
Thus, the test statistic value is 1.148.
Compute the p-value of the test as follows:
[tex]p-\text{value}=P(t_{n-1}<t)[/tex]
[tex]=P(t_{6-1}<1.148})\\\\=P(t_{5}<1.148})\\\\=0.1515[/tex]
*Use a t-table.
Thus, the p-value of the test is 0.1515.
Decision rule:
If the p-value of the test is less than the significance level then the null hypothesis will be rejected and vice-versa.
p-value = 0.1515 > α = 0.05
The null hypothesis will not be rejected at 5% level of significance.
Thus, concluding that the mean level of arsenic in chicken from the suppliers is 80 ppb.
Dr. Miriam Johnson has been teaching accounting for over 20 years. From her experience, she knows that 60% of her students do homework regularly. Moreover, 95% of the students who do their homework regularly generally pass the course. She also knows that 85% of her students pass the course.
a. What is the probability that a student will do homework regularly and also pass the course?
b. What is the probability that a student will neither do homework regularly nor will pass the course?
c. Are the events "pass the course" and "do homework regularly" mutually exclusive? Explain.
d. Are the events "pass the course" and "do homework regularly" independent? Explain.
Answer:
a) The probability that a student will do homework regularly and also pass the course = P(H n P) = 0.57
b) The probability that a student will neither do homework regularly nor will pass the course = P(H' n P') = 0.12
c) The two events, pass the course and do homework regularly, aren't mutually exclusive. Check Explanation for reasons why.
d) The two events, pass the course and do homework regularly, aren't independent. Check Explanation for reasons why.
Step-by-step explanation:
Let the event that a student does homework regularly be H.
The event that a student passes the course be P.
- 60% of her students do homework regularly
P(H) = 60% = 0.60
- 95% of the students who do their homework regularly generally pass the course
P(P|H) = 95% = 0.95
- She also knows that 85% of her students pass the course.
P(P) = 85% = 0.85
a) The probability that a student will do homework regularly and also pass the course = P(H n P)
The conditional probability of A occurring given that B has occurred, P(A|B), is given as
P(A|B) = P(A n B) ÷ P(B)
And we can write that
P(A n B) = P(A|B) × P(B)
Hence,
P(H n P) = P(P n H) = P(P|H) × P(H) = 0.95 × 0.60 = 0.57
b) The probability that a student will neither do homework regularly nor will pass the course = P(H' n P')
From Sets Theory,
P(H n P') + P(H' n P) + P(H n P) + P(H' n P') = 1
P(H n P) = 0.57 (from (a))
Note also that
P(H) = P(H n P') + P(H n P) (since the events P and P' are mutually exclusive)
0.60 = P(H n P') + 0.57
P(H n P') = 0.60 - 0.57
Also
P(P) = P(H' n P) + P(H n P) (since the events H and H' are mutually exclusive)
0.85 = P(H' n P) + 0.57
P(H' n P) = 0.85 - 0.57 = 0.28
So,
P(H n P') + P(H' n P) + P(H n P) + P(H' n P') = 1
Becomes
0.03 + 0.28 + 0.57 + P(H' n P') = 1
P(H' n P') = 1 - 0.03 - 0.57 - 0.28 = 0.12
c) Are the events "pass the course" and "do homework regularly" mutually exclusive? Explain.
Two events are said to be mutually exclusive if the two events cannot take place at the same time. The mathematical statement used to confirm the mutual exclusivity of two events A and B is that if A and B are mutually exclusive,
P(A n B) = 0.
But, P(H n P) has been calculated to be 0.57, P(H n P) = 0.57 ≠ 0.
Hence, the two events aren't mutually exclusive.
d. Are the events "pass the course" and "do homework regularly" independent? Explain
Two events are said to be independent of the probabilty of one occurring dowant depend on the probability of the other one occurring. It sis proven mathematically that two events A and B are independent when
P(A|B) = P(A)
P(B|A) = P(B)
P(A n B) = P(A) × P(B)
To check if the events pass the course and do homework regularly are mutually exclusive now.
P(P|H) = 0.95
P(P) = 0.85
P(H|P) = P(P n H) ÷ P(P) = 0.57 ÷ 0.85 = 0.671
P(H) = 0.60
P(H n P) = P(P n H)
P(P|H) = 0.95 ≠ 0.85 = P(P)
P(H|P) = 0.671 ≠ 0.60 = P(H)
P(P)×P(H) = 0.85 × 0.60 = 0.51 ≠ 0.57 = P(P n H)
None of the conditions is satisfied, hence, we can conclude that the two events are not independent.
Hope this Helps!!!
(−p 2 +4p−3)(p 2 +2)
Answer:
[tex]-p^4+4p^3-5p^2+8p-6[/tex]
I hope this help you :)
Imagine you have a rectangular wooden block with dimensions of 10 cm x 3 cm x 8 cm (L x W x H). Required:a. What is the volume of your wooden block?b. What is the density of this wooden block if it has a mass of 168 g?
Answer:
a) The volume of the wooden block is 240 cm^3.
b) The density of the wooden block is 0.7 g/cm^3.
Step-by-step explanation:
The volume of the rectangular wooden block can be calculated as the multiplication of the length in each dimension: length, wide and height.
With dimensions 10 cm x 3 cm x 8 cm, the volume is:
[tex]V=L\cdot W\cdot H = 10\cdot 3\cdot 8=240[/tex]
The volume of the wooden block is 240 cm^3.
If we know that the mass of the wooden block is 168 g, we can calculate the density as:
[tex]\rho = \dfrac{M}{V}=\dfrac{168}{240}=0.7[/tex]
The density of the wooden block is 0.7 g/cm^3.
Please help with this problem
Answer:
The length of the short side is 14.5 units, the length of the other short side is 18.5 units, and the length of the longest side is 23.5 units.
Step-by-step explanation:
The Pythagorean Theorem
If a and b are the lengths of the legs of a right triangle and c is the length of the hypotenuse, then the sum of the squares of the lengths of the legs is equal to the square of the length of the hypotenuse.
This relationship is represented by the formula:
[tex]a^2+b^2=c^2[/tex]
Applying the Pythagorean Theorem to find the lengths of the three sides we get:
[tex](x)^2+(x+4)^2=(x+9)^2\\\\2x^2+8x+16=x^2+18x+81\\\\2x^2+8x-65=x^2+18x\\\\2x^2-10x-65=x^2\\\\x^2-10x-65=0[/tex]
Solve with the quadratic formula
[tex]\mathrm{For\:a\:quadratic\:equation\:of\:the\:form\:}ax^2+bx+c=0\mathrm{\:the\:solutions\:are\:}[/tex]
[tex]x_{1,\:2}=\frac{-b\pm \sqrt{b^2-4ac}}{2a}[/tex]
[tex]\mathrm{For\:}\quad a=1,\:b=-10,\:c=-65:\quad x_{1,\:2}=\frac{-\left(-10\right)\pm \sqrt{\left(-10\right)^2-4\cdot \:1\left(-65\right)}}{2\cdot \:1}\\\\x_{1}=\frac{-\left(-10\right)+ \sqrt{\left(-10\right)^2-4\cdot \:1\left(-65\right)}}{2\cdot \:1}=5+3\sqrt{10}\\\\x_{2}=\frac{-\left(-10\right)- \sqrt{\left(-10\right)^2-4\cdot \:1\left(-65\right)}}{2\cdot \:1}=5-3\sqrt{10}[/tex]
Because a length can only be positive, the only solution is
[tex]x=5+3\sqrt{10}\approx 14.5[/tex]
The length of the short side is 14.5, the length of the other short side is [tex]14.5+4=18.5[/tex], and the length of the longest side is [tex]14.5+9=23.5[/tex].
Type the correct answer in the box. Use numerals instead of words. If necessary, use / for the fraction bar. In a talent competition, half of the contestants are eliminated in each round. At the end of the nth round, 32 contestants remain. If there were 1,024 contestants at the start of the competition, what is the value of n? The value of n is .
Answer:
n =32
Step-by-step explanation:
If 1 contestant is eliminated each round
then of 1024contestants
32 left
1024/32=32
Answer:
n=32
Step-by-step explanation:
Lucy has to run two errands. She starts from home and travels 3 miles south to the post office. From the post office, she travels 4 miles east to the gas station. Then, from the gas station, she travels 5 miles to return home. The entire trip forms a triangle. What was the smallest angle made at her trip? A. At the gas station B. At Lucy's home C. At the post office D. It depends on the direction she is traveling
Answer:
the correct choice is A. At the gas station
Step-by-step explanation:
Lucy starts at home and travels 3 miles south to the post office. From the post office, she travels 4 miles east to the gas station. As it is known south and east directions form right angle. Since the entire trip forms a triangle, this triangle is right with right angle at the post office.
Call the vertices of this triangle P - post office, G - gas station, H - home. Then HP and PG are legs of this triangle and GH is hypotenuse.
From the given data:
HP=3;
PG=4;
GH=5;
∠P=90°.
The smallest angle is opposite to the smallest side. The smallest side is leg HP, so the smallest angle is G that is the angle at gas station.
Answer:
a
Step-by-step explanation:
Single adults: According to a Pew Research Center analysis of census data, in 2012, 20% of American adults ages 25 and older had never been married. Suppose that we select 3 random samples of 500 adults from this population. Which of the following is most likely to occur with the three samples?
A. The number that had never been married will equal 20% in each of the three samples.B. The number that had never been married will vary in each sample due to the random selection of adults.C. The average for the three samples of the number of adults that had never been married will equal 20%.D. The number of adults that had never been married will increase for each sample because the number is generally increasing over time.
Answer:
Option B
Step-by-step explanation:
The number that had never been married will vary in each sample due to the random selection of adults.
This number will vary in each sample to the random selection process but they might or might not be as close as possible to one another after sampling.
On a coordinate plane, a line goes through points (0, 1) and (3, 0). Y = one-half x minus 1. Identify the slope of the graphed line: Identify the y-intercept of the graphed line: Identify the slope of the line given by the equation: Identify the y-intercept of the line given
Answer:
(a)
[tex]Slope=-\dfrac{1}{3}\\$y-intercept =1[/tex]
(b)
[tex]Slope = \dfrac12\\$y-intercept=$ -1[/tex]
Step-by-step explanation:
Given a line which goes through the points: (0, 1) and (3, 0).
(a)Slope
[tex]m=\dfrac{0-1}{3-0}\\m=-\dfrac{1}{3}[/tex]
The slope-intercept form of the equation of a line is given as: y=mx+b
Therefore:
[tex]y=-\dfrac{1}{3}x+b\\$From the point (0,1), When x=0, y=1; Therefore:$\\1=-\dfrac{1}{3}(0)+b\\$Therefore:\\b=1[/tex]
The y-intercept of the line through points (0, 1) and (3, 0) is 1.
(b)Given the line:
[tex]y=\dfrac12x-1[/tex]
Comparing with the slope-intercept form of the equation of a line: y=mx+b
[tex]Slope = \dfrac12\\$y-intercept=$ -1[/tex]
Answer:
Identify the slope of the graphed line:
✔ -1/3
Identify the y-intercept of the graphed line:
✔ 1
Identify the slope of the line given by the equation:
✔ 1/2
Identify the y-intercept of the line given by the equation:
✔ -1
Step-by-step explanation:
Got it right on edge. 2020
:)) hope I helped.
Solve for x: −3x + 3 < 6
Answer:x>-1
Step-by-step explanation:
Step 1: Subtract 3 from both sides.
-3x+3-3<6-3
-3x<3
Step 2: Divide both sides by -3.
-3x/-3<3/3
X>-1
Among coffee drinkers, men drink a mean of 3.2 cups per day with a standard deviation of 0.8 cups. Assume the number of cups per day follows a normal distribution.
a. What proportion drink 2 cups per day or more?
b. What proportion drink no more than 4 cups per day?
c. If the top 5% of coffee drinkers are considered "heavy" coffee drinkers, what is the minimum number of cups consumed by a heavy coffee drinker?
d. If a sample of 20 men is selected, what is the probability that the mean number of cups per day is greater than 3?
Answer:
a) 0.9332 = 93.32% drink 2 cups per day or more.
b) 0.8413 = 84.13% drink no more than 4 cups per day
c) The minimum number of cups consumed by a heavy coffee drinker is 4.52.
d) 86.86% probability that the mean number of cups per day is greater than 3
Step-by-step explanation:
To solve this question, we need to understand the normal probability distribution and the central limit theorem.
Normal probability distribution
When the distribution is normal, we use the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
Central Limit Theorem
The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
In this question, we have that:
[tex]\mu = 3.2, \sigma = 0.8[/tex]
a. What proportion drink 2 cups per day or more?
This is 1 subtracted by the pvalue of Z when X = 2. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{2 - 3.2}{0.8}[/tex]
[tex]Z = -1.5[/tex]
[tex]Z = -1.5[/tex] has a pvalue of 0.0668
1 - 0.0668 = 0.9332
0.9332 = 93.32% drink 2 cups per day or more.
b. What proportion drink no more than 4 cups per day?
This is the pvalue of Z when X = 4.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{4 - 3.2}{0.8}[/tex]
[tex]Z = 1[/tex]
[tex]Z = 1[/tex] has a pvalue of 0.8413
0.8413 = 84.13% drink no more than 4 cups per day
c. If the top 5% of coffee drinkers are considered "heavy" coffee drinkers, what is the minimum number of cups consumed by a heavy coffee drinker?
This is the 100 - 5 = 95th percentile, which is X when Z has a pvalue of 0.95. So X when Z = 1.645. Then
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]1.645 = \frac{X - 3.2}{0.8}[/tex]
[tex]X - 3.2 = 1.645*0.8[/tex]
[tex]X = 4.52[/tex]
The minimum number of cups consumed by a heavy coffee drinker is 4.52.
d. If a sample of 20 men is selected, what is the probability that the mean number of cups per day is greater than 3?
Sample of 20, so applying the central limit theore with n = 20, [tex]s = \frac{0.8}{\sqrt{20}} = 0.1789[/tex]
This probability is 1 subtracted by the pvalue of Z when X = 3.
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]Z = \frac{3 - 3.2}{0.1789}[/tex]
[tex]Z = -1.12[/tex]
[tex]Z = -1.12[/tex] has a pvalue of 0.1314
1 - 0.1314 = 0.8686
86.86% probability that the mean number of cups per day is greater than 3
The answer to – 7x + y = -10
Step-by-step explanation:
y=7x-10
Answer:
[tex]\huge \boxed{y=7x-10}[/tex]
Step-by-step explanation:
[tex]-7x+y=-10[/tex]
[tex]\sf Add \ 7x \ on \ both \ sides.[/tex]
[tex]-7x+y+7x=-10+7x[/tex]
[tex]y=7x-10[/tex]
Please help !! Correct and first answer I’ll give you brainesttttt ! What is the equation of the line?
Step-by-step explanation:
can u give image PlZzzzz ....
Answer:
Hey!
Your answer should be Y=2x+4
Step-by-step explanation:
Hope this helps!
Select a composite number to break into factors. Continue factoring until all factors are prime
Answer:
2*2 * 2*2 * 2*3
Step-by-step explanation:
96 =16 *6
Break these down, since neither 16 nor 6 are prime
= 4*4 * 2*3
4 in not prime, but 2 and 3 are prime
= 2*2 * 2*2 * 2*3
All of these are prime
Answer:
22, 23
Step-by-step explanation:
Just got it right on edge 2021
Can someone plz help me solved this problem! I’m giving you 10 points! I need help plz help me! Will mark you as brainiest!
Answer:
See the answers below.
Step-by-step explanation:
[tex]a.\:\frac{f\left(x\right)-f\left(a\right)}{x-a}=\frac{2x^2-x-5-\left(2a^2-a-5\right)}{x-a}\\\\=\frac{2x^2-x+a-2a^2}{x-a}\\\\=\frac{2\left(x+a\right)\left(x-a\right)-1\left(x-a\right)}{x-a}\\\\=\frac{\left(x-a\right)\left[2\left(x+a\right)-1\right]}{x-a}\\\\=2x+2a-1\\\\\\b.\:\frac{f\left(x+h\right)-f\left(x\right)}{h}=\frac{2\left(x+h\right)^2-\left(x+h\right)-5-\left(2x^2-x-5\right)}{h}\\\\=\frac{2\left(x^2+2xh+h^2\right)-\left(x+h\right)-5-\left(2x^2-x-5\right)}{h}\\[/tex]
Expand and simplify to get:
[tex]=\frac{2h^2+4xh-h}{h}\\\\=\frac{h\left(2h+4x-1\right)}{h}\\\\=2h+4x-1[/tex]
Best Regards!
100 pts You have a bag of 15 marbles: 5 blue, 3 red, 4 green, and 3 yellow. You draw 3 marbles without replacement. Which action, performed before the draws, increases the probability of drawing 3 green marbles in a row?
Answer:
see below
Step-by-step explanation:
You can remove one or more of the other color marbles to increase the probability of drawing a green marble
or
You can add one or more green marbles to have more green marbles in the bag
Any help would be greatly appreciated
Answer: 267.9
Step-by-step explanation:
Since we are given the radius, we can plug it into the equation given.
[tex]V=\frac{4}{3} \pi (4)^3[/tex]
[tex]V=\frac{4}{3} \pi (64)[/tex]
[tex]V=267.9[/tex]
Rod's quiz grades are 72, 74, 89, and90. What score on a fifth quiz will make his average woz grade at least 84?
Answer: He would need at least a 95
Step-by-step explanation:
First I found the current average by adding 72, 74, 89, and 90 which equals 325.
Second, I worked backwards to see what the sum of his grades had to be by multiplying 84 times 5. 84 times 5 = 420
Now that we have both the current and the target sum, we find the difference by doing 420-325 which equals 95.
State the size of angle 'n' in the triangle illustrated below.
Answer:
Option B
Step-by-step explanation:
<r = 32 degrees (alternate angles )
<r = <n = 32 degrees (vertical angles)
According to the National Association of Theater Owners, the average price for a movie in the United States in 2012 was $7.96. Assume the population standard deviation is $0.50 and that a sample of 30 theaters was randomly selected.
Required:
a. Calculate the standard error of the mean.
b. What is the probability that the sample mean will be less than $7.75?
c. What is the probability that the sample mean will be less than $8.10?
d. What is the probability that the sample mean will be more than $8.20?
Answer:
(a) The standard error of the mean is 0.091.
(b) The probability that the sample mean will be less than $7.75 is 0.0107.
(c) The probability that the sample mean will be less than $8.10 is 0.9369.
(d) The probability that the sample mean will be more than $8.20 is 0.0043.
Step-by-step explanation:
We are given that the average price for a movie in the United States in 2012 was $7.96.
Assume the population standard deviation is $0.50 and that a sample of 30 theaters was randomly selected.
Let [tex]\bar X[/tex] = sample mean price for a movie in the United States
The z-score probability distribution for the sample mean is given by;
Z = [tex]\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }[/tex] ~ N(0,1)
where, [tex]\mu[/tex] = population mean price for a movie = $7.96
[tex]\sigma[/tex] = population standard deviation = $0.50
n = sample of theaters = 30
(a) The standard error of the mean is given by;
Standard error = [tex]\frac{\sigma}{\sqrt{n} }[/tex] = [tex]\frac{0.50}{\sqrt{30} }[/tex]
= 0.091
(b) The probability that the sample mean will be less than $7.75 is given by = P([tex]\bar X[/tex] < $7.75)
P([tex]\bar X[/tex] < $7.75) = P( [tex]\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }[/tex] < [tex]\frac{7.75-7.96}{\frac{0.50}\sqrt{30} } }[/tex] ) = P(Z < -2.30) = 1 - P(Z [tex]\leq[/tex] 2.30)
= 1 - 0.9893 = 0.0107
The above probability is calculated by looking at the value of x = 2.30 in the z table which has an area of 0.9893.
(c) The probability that the sample mean will be less than $8.10 is given by = P([tex]\bar X[/tex] < $8.10)
P([tex]\bar X[/tex] < $8.10) = P( [tex]\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }[/tex] < [tex]\frac{8.10-7.96}{\frac{0.50}\sqrt{30} } }[/tex] ) = P(Z < 1.53) = 0.9369
The above probability is calculated by looking at the value of x = 1.53 in the z table which has an area of 0.9369.
(d) The probability that the sample mean will be more than $8.20 is given by = P([tex]\bar X[/tex] > $8.20)
P([tex]\bar X[/tex] > $8.20) = P( [tex]\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }[/tex] > [tex]\frac{8.20-7.96}{\frac{0.50}\sqrt{30} } }[/tex] ) = P(Z > 2.63) = 1 - P(Z [tex]\leq[/tex] 2.63)
= 1 - 0.9957 = 0.0043
The above probability is calculated by looking at the value of x = 2.63 in the z table which has an area of 0.9957.
fill the blank with , or = please help quick!
Answer:
44. answer = a. (<)
45. answer = b. (>)
Step-by-step explanation:
To find the relation between the angles, we can use the law of sines in the triangle that contains both angles.
So for question 44, the angles mQRW and mRWQ are both in the triangle QWR, so we have:
10 / sin(mQRW) = 17 / sin(mRWQ)
sin(mQRW) / sin(mRWQ) = 10 / 17
The bigger the sine of the angle, the bigger the angle, so if the ratio between the sine of mQRW and sine of mRWQ is lesser than 1, the angle mQRW is lesser than the angle mRWQ (correct option: a.)
In the same way, in the question 45, the angles mRTW and mTWR are both in the triangle TWR, so we have:
15 / sin(mRTW) = 8 / sin(mTWR)
sin(mRTW) / sin(mTWR) = 15 / 8
If the ratio between the sine of mRTW and sine of mTWR is greater than 1, the angle mRTW is greater than the angle mTWR (correct option: b.)
Basically, the angle opposite to the greater side is the greater angle, and the angle opposite to the smaller side is the smaller angle.
Determine the axis of symmetry and the vertex of the given function. y = 2x2 − 12x + 21 Axis of symmetry:
Answer:
Equation of the axis of symmetry is: x = 3
Step-by-step explanation:
The equation
[tex]y=2x^2-12x+21[/tex]
is the equation of a parabola, of the form
[tex]y=ax^2+bx+c[/tex] whose vertex is located at the x-coordinate:
[tex]x_{vertex}=\frac{-b}{2\,a}[/tex]
Then, for our case the x position of the given parabola, is:
[tex]x_{vertex}=\frac{-b}{2\,a} \\x_{vertex}=\frac{12}{2\,(2)} \\x_{vertex}=3[/tex]
Then the equation of the axis of symmetry, which is a vertical line that goes through the vertex, would be given by:
x = 3
PROBLEM 6. 10 A histogram has mean 70 and standard deviation 5 If the histogram is not bell shaped but it is symmetric. Find the least proportion of data falls between 70 and 80 If the histogram is bell shaped. Find the proportion of data between 65 and 77
Answer:
a. 0.4772 = 47.72 %
b. 0.7605 = 76.05 %
Step-by-step explanation:
What we must do is calculate the z value for each value and thus find what percentage each represents and the subtraction would be the percentage between those two values.
We have that z is equal to:
z = (x - m) / (sd)
x is the value to evaluate, m the mean, sd the standard deviation
a. ind the least proportion of data falls between 70 and 80 If the histogram is bell shaped:
So for 70 copies we have:
z = (70 - 70) / (5)
z = 0
and this value represents 0.5
So for 80 copies we have:
z = (80 - 70) / (5)
z = 2
and this value represents 0.9772
p (70 > x > 80) = 0.9772 - 0.5
p (70 > x > 80) = 0.4772 = 47.72 %
b. Find the proportion of data between 65 and 77
So for 65 copies we have:
z = (65 - 70) / (5)
z = -1
and this value represents 0.1587
So for 77 copies we have:
z = (77 - 70) / (5)
z = 1.4
and this value represents 0.9192
p (65 > x > 77) = 0.9192 - 0.1587
p (65 > x > 77) = 0.7605 = 76.05 %
The mean life of a particular brand of light bulb is 1200 hours and the standard deviation is 75 hours. Tests show that the life of the bulb is approximately normally distributed. It can be concluded that approximately 68% of the bulbs will last between:_________
Answer:
[tex] \mu -\sigma = 1200-75 = 1125[/tex]
[tex] \mu +\sigma = 1200+75 = 1275[/tex]
It can be concluded that approximately 68% of the bulbs will last between:1125 and 1275 hours
Step-by-step explanation:
For this case we know that the random variable X "iife of a particular brand of light bulb " and we know the following distribution:
[tex] X \sim N(\mu = 1200, \sigma =75)[/tex]
And we can use the empirical rule for this case and we know that 68% of the values are within one deviation from the mean and we can find the limits like this:
[tex] \mu -\sigma = 1200-75 = 1125[/tex]
[tex] \mu +\sigma = 1200+75 = 1275[/tex]
It can be concluded that approximately 68% of the bulbs will last between:1125 and 1275 hours
An elementary school is offering 3 language classes: one in Spanish, one in French, and one in German. The classes are open to any of the 100 students in the school. There are 28 students in the Spanish class, 26 in the French class, and 16 in the German class. There are 12 students who are in both Spanish and French, 4 who are in both Spanish and German, and 6 who are in both French and German. In addition, there are 2 students taking all 3 classes. If two students are randomly chosen, what is the probability that at exactly one of them does exactly two language classes.
Answer:
The probability that at exactly one of them does exactly two language classes is 0.32.
Step-by-step explanation:
We can model this variable as a binomial random variable with sample size n=2.
The probability of success, meaning the probability that a student is in exactly two language classes can be calculated as the division between the number of students that are taking exactly two classes and the total number of students.
The number of students that are taking exactly two classes is equal to the sum of the number of students that are taking two classes, minus the number of students that are taking the three classes:
[tex]N_2=F\&S+S\&G+F\&G-F\&S\&G=12+4+6-2=20[/tex]
Then, the probabilty of success p is:
[tex]p=20/100=0.2[/tex]
The probability that k students are in exactly two classes can be calcualted as:
[tex]P(x=k) = \dbinom{n}{k} p^{k}(1-p)^{n-k}\\\\\\P(x=k) = \dbinom{2}{k} 0.2^{k} 0.8^{2-k}\\\\\\[/tex]
Then, the probability that at exactly one of them does exactly two language classes is:
[tex]P(x=1) = \dbinom{2}{1} p^{1}(1-p)^{1}=2*0.2*0.8=0.32\\\\\\[/tex]
You are surveying people exiting from a polling booth and asking them if they voted independent. The probability (p) that a person voted independent is 20%. What is the probability that 15 people must be asked before you can find 5 people who voted independen
Answer:
Step-by-step explanation:
Let the distribution law followed is exponential law .
mean m = np where n = 15 , p = .2
m = 15 x .2 = 3
probability of 5 successes
= [tex]\frac{e^{-m}m^r}{r!}[/tex]
= [tex]\frac{e^{-3}3^5}{5!}[/tex]
= .1
y= -3/2x-6 x=15 plssssssssssssssssssssssss help
Answer:
-45/2 - 12/2 = -57/2
Step-by-step explanation:
Substitute 15 for x in the given equation: y = (-3/2)x - 6 becomes
y = (-3/2)(15) - 6 = -45/2 - 6 when x = 15. This is equivalent to -57/2
B
Round your answer to the nearest hundredth.
A
9
B
5
Answer:
56.25°
Step-by-step explanation:
The definition of the cosine function tells you that
cos(B) = BC/BA
B = arccos(BC/BA) = arccos(5/9)
B ≈ 56.25°
Please answer this correctly
Answer:
30
Step-by-step explanation:
Answer:
It would decrease by 9.
Step-by-step explanation:
52 is the original mean or the initial mean.
43 is the final mean.
52-43 = 9
So 9 is the difference.
Hope this helped!