Answer:
the gram
Step-by-step explanation:
casegunnell is my gram, follow if your a real g
Following are the calculation to the given points:
When the ABCD is parallelogram:
The properties of parallelogram:
[tex]\to \angle CBD = \angle ADB \\\\[/tex]
[tex]\to \angle BCA = \angle DAC \\\\[/tex]
When the Two-lines are parallel and alternate interior angles are equal:
[tex]\to \Delta BEC \cong \Delta AED \ \ \ \ \ \ \ \{ASA\} \\\\\to \overline {AE} \cong \overline{CE}\\\\ \to \overline{BE} \cong \overline{ED} \\\\[/tex]
When the properties of congruent triangle.
Learn more:
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Antipsychotic drugs are widely prescribed for conditions such as schizophrenia and bipolar disease. An article reported on body composition and metabolic changes for individuals who had taken various antipsychotic drugs for short periods of time. (a) The sample of 41 individuals who had taken aripiprazole had a mean change in total cholesterol (mg/dL) of 3.55, and the estimated standard error sD n was 3.478. Calculate a confidence interval with confidence level approximately 95% for the true average increase in total cholesterol under these circumstances. (Round your answers to two decimal places.)
Answer:
95% for the true average increase in total cholesterol under these circumstances
(-2.306 , 9.406)
Step-by-step explanation:
Step(i):-
Given sample size 'n' =41
Mean of the sample(x⁻) = 3.55
The estimated standard error
[tex]S.E = \frac{S.D}{\sqrt{n} }[/tex]
Given estimated standard error ( S.E) = 3.478
Level of significance ∝=0.05
Step(ii):-
95% for the true average increase in total cholesterol under these circumstances
[tex](x^{-} - t_{0.05} S.E ,x^{-} + t_{0.05} S.E)[/tex]
Degrees of freedom
ν= n-1 = 41-1 =40
t₀.₀₅ = 1.6839
95% for the true average increase in total cholesterol under these circumstances
[tex](x^{-} - t_{0.05} S.E ,x^{-} + t_{0.05} S.E)[/tex]
( 3.55 - 1.6839 ×3.478 ,3.55 + 1.6839 ×3.478 )
(3.55 - 5.856 , 3.55 + 5.856)
(-2.306 , 9.406)
Conclusion:-
95% for the true average increase in total cholesterol under these circumstances
(-2.306 , 9.406)
Diana works in a building that is 130 feet tall. She is outside, looking up at the building at an angle of 37° from her feet to the top of the building. If Diana walks forward and her angle looking to the top of the building changes to 40°, how much closer is she to the building? Round the answer to the nearest tenth of a foot.
Answer:
Let x be her initial distance from the building, then tan 37 = 130/x
x = 130/tan 37 = 130/0.7536 = 172.5 feet
Let y be her distance from the building after moving forward, then
tan 40 = 130/y
y = 130/tan 40 = 130/0.8391 = 154.9
After moving forward, she is 172.5 - 154.9 = 17.6 ft closer.
Answer: B. 17.6 ft.
Step-by-step explanation: I just did it on the edge 2023 assignment. Check attached image.
Nicola runs a small pottery cafe. Customers choose from a range of ceramics which they paint and personalise.
Nicola wants to make as much profit as possible on the sale of ceramic plates. She pays £1.28 for each plate. What is the most profit Nicola can make on one plate.
Answer:
Bb
Step-by-step explanation:
A zorb is a large inflated ball within a ball. The formula for the radius r of a sphere with surface area A is given by requalsStartRoot StartFraction Upper A Over 4 pi EndFraction EndRoot . Calculate the radius of a zorb whose outside surface area is
Answer:
radius r of the zorb is ≅ 1.40 m
Step-by-step explanation:
GIven that;
the radius r of a sphere with surface area A is given by;
[tex]r = \sqrt{\dfrac {A}{4 \pi }}[/tex] which is read as : (r equals StartRoot StartFraction Upper A Over 4 pi EndFraction EndRoot .)
We are to calculate the radius of a zorb whose outside surface area is 24.63 sq ( the missing part of the question)
Given that the outside surface area is : 24.63 sq
Let replace the value of the outside surface area which 24.63 sq for A in the equation given from above.
SO: A = 24.63 sq
[tex]r = \sqrt{\dfrac {A}{4 \pi }}[/tex]
[tex]r = \sqrt{\dfrac {24.63}{4 \pi }}[/tex]
[tex]r = \sqrt{1.9599}[/tex]
r = 1.399
radius r of the zorb is ≅ 1.40 m
EASY MIDDLE SCHOOL MATH WITH INSTANT BRAINIEST AND MANY POINTS, PLZ HELP!!!
Answer:
Second option is the correct choice. See the explanation below.
Step-by-step explanation:
[tex]A=\frac{bh}{2}\\\\\mathrm{Switch\:sides}:\\\\\frac{bh}{2}=A\\\\\mathrm{Multiply\:both\:sides\:by\:}2\\\\\frac{2bh}{2}=2A\\\\hb=2A\\\\\mathrm{Divide\:both\:sides\:by\:}b;\\\\\frac{hb}{b}=\frac{2A}{b}\\\\h=\frac{2A}{b}[/tex]
Best Regards!
Answer:
[tex]h = \frac{2A}{b} [/tex]
Option B is the right option.
Solution,
[tex]a = \frac{bh}{2} \\ 2a = bh(cross \: multiplication) \\ 2a = b \times h \\ h = \frac{2A}{b} [/tex]
hope this helps...
Good luck on your assignment..
angle ∠DAC= angle ∠BAD. What is the length of BD? Round to one decimal place.
Answer: 3.9
Step-by-step explanation: Khan Academy
The length of BD if The angle ∠ DAC is equal to the angle ∠ BAD is 3.92.
What is the triangle?Three straight lines coming together create a triangle. There are three sides and three corners on every triangle (angles). A triangle's vertex is the intersection of two of its sides. Any one of a triangle's three sides can serve as its base, however typically the bottom side is used.
Given:
The angle ∠ DAC = angle ∠ BAD
As we can see that the triangle BAD and triangle DAC are similar By SAS similarity,
AC / AB = CD / BD (By the proportional theorem of similarity)
5.6 / 5.1 = 4.3 / BD
1.09 = 4.3 / BD
BD = 4.3 / 1.09
BD = 3.92
Thus, the length of BD is 3.92.
To know more about Triangles:
https://brainly.com/question/16886469
#SPJ2
Consider random samples selected from the population of all female college soccer players in the United States. Assume the mean height of female college soccer players in the United States is 66 inches and the standard deviation is 3.5 inches. Which do you expect to have less variability (spread): a sampling distribution with sample size n
Answer:
Option C is correct.
The sampling distribution with sample size n=100 will have less variability.
Step-by-step explanation:
Complete Question
Consider random samples selected from the population of all female college soccer players in the United States. Assume the mean height of female college soccer players in the United States is 66 inches and the standard deviation is 3.5 inches. Which do you expect to have less variability (spread): a sampling distribution with sample size n = 100 or a sample size of n = 20.
A. Both sampling distributions will have the same variability.
B.The sampling distribution with sample size n=20 will have less variability
C. The sampling distribution with sample size n =100 will have less variability
Solution
The central limit theorem allows us to say that as long as
- the sample is randomly selected from the population distribution with each variable independent of each other and with the sample having an adequate enough sample size.
- the random sample is normal or almost normal which is guaranteed if the population distribution that the random sample was extracted from is normal or approximately normal,
1) The mean of sampling distribution (μₓ) is approximately equal to the population mean (μ)
μₓ = μ = 66 inches
2) The standard deviation of the sampling distribution or the standard error of the sample mean is related to the population standard deviation through
σₓ = (σ/√N)
where σ = population standard deviation = 3.5 inches
N = Sample size
And the measure of variability for a sampling distribution is the magnitude of the standard deviation of the sampling distribution.
For sampling distribution with sample size n = 100
σₓ = (3.5/√100) = 0.35 inch
For sampling distribution with sample size n = 20
σₓ = (3.5/√20) = 0.7826 inch
The standard deviation of the sampling distribution with sample size n = 20 is more than double that of the sampling distribution with sample size n = 100, hence, it is evident that the bigger the sample size, the lesser the standard deviation of the sampling distribution and the lesser the variability that the sampling distribution shows.
Hope this Helps!!!
Please answer this question I give brainliest thank you! Number 8
Answer:
The third options
Step-by-step explanation:
Counting we can see that 10 students went to two or less states, and 10 went to three or more
A grocery store manager notices that this month her store sold a total of 597 gallons of ice cream, which represents a decrease of 15% from last month. On the other hand, her store sold 617 pounds of broccoli this month, which represents an increase of 21% from last month. How much ice cream and broccoli did the store sell last month? Round your answers to the nearest integer.
Answer:
(a)The total sales of ice-cream last month is 702 gallons.
(b)The total sales of broccoli last month is 510 pounds.
Step-by-step explanation:
Part A
Total Sales of gallons of ice cream this month = 597
Since it represents a decrease of 15% of last month's sales
Let the total sales of ice-cream last month =x
Then:
(100-15)% of x =597
85% of x=597
0.85x=597
x=597/0.85
x=702 (to the nearest integer)
The total sales of ice-cream last month is 702 gallons.
Part B
Total Sales of broccoli this month = 617 pounds
Since it represents an increase of 21% of last month's sales
Let the total sales of ice-cream last month =y
Then:
(100+21)% of y =617
121% of y=617
1.21y=617
y=617/1.21
y=510 (to the nearest integer)
The total sales of broccoli last month is 510 pounds.
A sample of 75 information systems managers had an average hourly income of $40.75 with a standard deviation of $7.00. The 95% confidence interval for the average hourly wage (in $) of all information system managers is
Answer:
The 95% confidence interval for the average hourly wage of all information system managers is (39.14,42.36)
Step-by-step explanation:
In order to calculate the 95% confidence interval for the average hourly wage we would have to calculate first the margin of error as follows:
ME=t0.05/2,n-1s/√n
for n=75, t0.025,74=1.993
Therefore, ME=1.993*7/√75
ME=1.61
Therefore, the 95% confidence interval for the average hourly income of all syatem manager would be as follows:
(X-ME,X+ME)=(40.75-1.61,40.75+1.61)
=(39.14,42.36)
A research organization keeps track of what citizens think is the most important problem facing the country today. They randomly sampled a number of people in 2003 and again in 2009 using a different random sample of people in 2009 than in 2003 and asked them to choose the most important problem facing the country today from the following choices, war, economy, health care, or other. Which of the following is the correct test to use to determine if the distribution of "problem facing this countrytoday" is different between the two different years?
A.
Use a chi-square test of homogeneity.
B.
Use a paired t-test.
C.
Use a two-sample z-test for proportions.
D.
Use a chi-square goodness-of-fit test.
Answer:
Step-by-step explanation:
From the information given, the population is divided into sub groups. Each group would consist of citizens picking a particular choice as the most important problem facing the country. The choices are the different categories. In this case, the null hypothesis would state that the distribution of proportions for all categories is the same in each population. The alternative hypothesis would state that the distributions is different. Therefore, the correct test to use to determine if the distribution of "problem facing this country today" is different between the two different years is
A) Use a chi-square test of homogeneity.
The World Issues club has decided to donate 60% of all their fundraising activities this year to Stephen Lewis Foundation. This foundation was created to help ease the pain of HIV/AIDS in Africa. Lewis, a Canadian, works for the United Nations trying to determine ways to stop the spread of this deadly disease from crippling an entire continent. Choose a variable to represent the money earned during fundraising activities and the revenue generated for the foundation Use these variables to create an equation that will determine the amount of money the foundation will receive. In their latest bake sale, the club raised $72. Calculate the amount the foundation will receive. At the end of the year, the World Issues Club mailed a cheque to the foundation for $850. How much money did they fundraise in total?
Answer:
$43.20$1416.67Step-by-step explanation:
Let the money earned during fundraising activities =x
Since the World Issues club has decided to donate 60% of all their fundraising activities this year to Stephen Lewis Foundation.
The amount of money the foundation will receive
=60% of x
= 0.6x
In the bake sale, the club raised $72.
Therefore, the amount the foundation will receive =0.6*72=$43.20
At the end of the year, the World Issues Club mailed a cheque to the foundation for $850.
Therefore:
0.6x=850
x=850/0.6
x=$1416.67
The total amount of money the club raised is $1416.67.
pls helppppp with my math
Answer:
[tex]\frac{1}{6}[/tex]
Step-by-step explanation:
Answer:
Step-by-step explanation:
[tex]\frac{5}{6}-\frac{2}{3}=\frac{5}{6}-\frac{2*2}{3*2}\\\\=\frac{5}{6}-\frac{4}{6}\\\\=\frac{5-4}{6}\\\\=\frac{1}{6}[/tex]
In the multiplication sentence below, which numbers are the factors? Check
all that apply.
10 x 8 = 80
A. 80
B. 8.
I C. 10
Answer:
10 and 8
Step-by-step explanation:
10 and 8 are the factors in this equation because factors are the numbers that are mutiplied together to get the product (The answer to a mutiplication problem) Therefore the factors in this equation are 10 and 8 because those are the numbers that are mutiplied together to get the product.
1. A random sample of 64 customers at a drive-through bank window is observed, and it is found that the teller spends an average of 2.8 minutes with each customer, with a standard deviation of 1.2 minutes. Is there sufficient evidence to conclude that the teller spends less than 3 minutes with each customer
Answer:
The 95% confidence interval is 2.5 < u <3.1.
Step-by-step explanation:
The provided sample mean is X = 2.8 and the sample standard deviation is s = 1.2, and the sample size is n = 64.
1. Null and Alternative Hypotheses:
The following null and alternative hypotheses need to be tested:
H0 u = 3
Ha: u < 3
This corresponds to a left-tailed test, for which a t-test for one mean, with unknown population standard deviation will be used.
2. Rejection Region Based
on the information provided, the significance level is alpha = 0.05, and the critical value for a left-tailed test is t c = -1.669.
The rejection region for this left-tailed test is R = t : t < -1.669
3. Test Statistics
The t-statistic is computed as follows:
t = (X - uo)/[s/n^(1/2)] =
replacing
t = (2.8 - 3)/ [1.2/64 ^(1/2)]
t =-1.333
4. Decision about the null hypothesis
Since it is observed that t = -1.333 > t c = -1.669, it is then concluded that the null hypothesis is not rejected.
Using the P-value approach: The p-value is p = 0.0936, and since p= 0.0936 => 0.05, it is concluded that the null hypothesis is not rejected.
5. Conclusion It is concluded that the null hypothesis H0 is not rejected. Therefore, there is not enough evidence to claim that the population mean u is less than 3, at the 0.05 significance level.
Confidence Interval
The 95% confidence interval is 2.5 < u <3.1.
The production department has installed a new spray machine to paint automobile doors. As is common with most spray guns, unsightly blemishes often appear because of improper mixtures or other problems. A worker counted the number of blemishes on each door. Most doors had no blemishes; a few had one; a very few had two; and so on. The average number was 0.5 per door. The distribution of blemishes followed the Poisson distribution. Out of 10,000 doors painted, about how many would have no blemishes
Answer:
The numbers of doors that will have no blemishes will be about 6065 doors
Step-by-step explanation:
Let the number of counts by the worker of each blemishes on the door be (X)
The distribution of blemishes followed the Poisson distribution with parameter [tex]\lambda =0.5[/tex] / door
The probability mass function on of a poisson distribution Is:
[tex]P(X=x) = \dfrac{e^{- \lambda } \lambda ^x}{x!}[/tex]
[tex]P(X=x) = \dfrac{e^{- \ 0.5 }( 0.5)^ x}{x!}[/tex]
The probability that no blemishes occur is :
[tex]P(X=0) = \dfrac{e^{- \ 0.5 }( 0.5)^ 0}{0!}[/tex]
[tex]P(X=0) = 0.60653[/tex]
P(X=0) = 0.6065
Assume the number of paints on the door by q = 10000
Hence; the number of doors that have no blemishes is = qp
=10,000(0.6065)
= 6065
NEED GEOMETRY HELP ASAP (12 POINTS)
Answer:
HJ > PK
Step-by-step explanation:
Notice that the side PL in one triangle has the same length as side GJ in the other, and side GH has the same size as side LK of the other triangle. Now what is different is the angle subtended between these sides in the case of the triangle on the lower left, the subtended angle is [tex]90^o[/tex] , which is larger angle than that subtended between equal sides on the other triangle ([tex]85^o[/tex])
Therefore, if the angle subtended by the equivalent sides in the triangle on the left is larger than the angle subtended on the right hand side triangle, then the sides associated with such angle aperture must keep the inequality. That is:
Since [tex]\angle\,G\,\,\,>\,\,\,\angle \,L[/tex], then HJ > PK
The average height of students at UH from an SRS of 12 students gave a standard deviation of 2.5 feet. Construct a 95% confidence interval for the standard deviation of the height of students at UH. Assume normality for the data.a. (1.271, 6.245)b. (0.771, 10.245)c. (1.771, 4.245)d. (7.771, 9.245)e. (4.771, 10.245)f. None of the above
Answer:
c. [1.771;4.245] feet
Step-by-step explanation:
Hello!
The variable of interest is
X: height of a student at UH
X~N(μ;σ²)
You have to estimate the population standard deviation using a 95% confidence interval.
The statistic to use for the interval is a student Chi-Square with n-1 degrees of freedom. First you have to calculate the CI for the population variance:
[tex][\frac{(n-1)S^2}{X^2_{n-1;1-\alpha /2}} ;\frac{(n-1)S^2}{X^2_{n-1;\alpha /2}} ][/tex]
[tex]X^2_{n-1;1-\alpha /2}= X^2_{11;0.975}= 21.920[/tex]
[tex]X^2_{n-1;\alpha /2}= X^2_{11;0.025}= 3.816[/tex]
n=12
S= 2.5
[tex][\frac{11*6.25}{21.920} ;\frac{11*6.25}{3.816}} ][/tex]
[3.136; 18.016] feet²
Then you calculate the square root of both limits to get the CI for the population standard deviation:
[√3.136; √18.016]
[1.771;4.245] feet
I hope this helps!
someone help please with this question
Step-by-step explanation:
1. 180 - (36 +36)= 108
2. angle ABC = 108 angle DBC = 108-72=36
3. angle DCB=angle DBC. This is because the base angles are equal
4 therefore triangle BDC is isoscles
Answer:
Because ΔABD is isosceles, ∠ABD ≅ ∠ADB = 72° because of Base Angles Theorem which states that the base angles of an isosceles triangle are congruent. Then, ∠BDC = 180° - ∠ADB = 108° because they are supplementary angles. Because ΔABC is isosceles, ∠BAC ≅ ∠BCA = 36° because of Base Angles Theorem, which means ∠CBD = 180° - 108° - 36° = 36° because of the sum of angles in a triangle. Therefore, ΔBCD is isosceles because of the Converse of Base Angles Theorem.
The assembly time for a product is uniformly distributed between 8 and 12 minutes.The mean and the variance of the assembly time are: a.4 minutes and 16 (minute)2 b.8 minutes and 12 (minute)2 c.12 minutes and 1.33 (minute)2 d.10 minutes and 1.33 (minute)2
Answer:
d. 10 minutes and 1.33 minutes.
Step-by-step explanation:
An uniform probability is a case of probability in which each outcome is equally as likely.
For this situation, we have a lower limit of the distribution that we call a and an upper limit that we call b.
The mean of the uniform distribution is:
[tex]M = \frac{a + b}{2}[/tex]
The variance of the uniform distribution is given by:
[tex]V = \frac{(b-a)^{2}}{12}[/tex]
The assembly time for a product is uniformly distributed between 8 and 12 minutes.
This means that [tex]a = 8, b = 12[/tex].
Mean:
[tex]M = \frac{8 + 12}{2} = 10[/tex]
Variance:
[tex]V = \frac{(12-8)^{2}}{12} = 1.33[/tex]
So the correct answer is:
d. 10 minutes and 1.33 minutes.
Find the following measure for this figure.
Volume =
Answer:
91 2/3 pi cubic units
Step-by-step explanation:
The formula for the volume of cone is [tex]\dfrac{1}{3}\pi r^2 h[/tex]. Plugging in the given numbers, you get:
[tex]\dfrac{1}{3}\cdot \pi \cdot 5^2 \cdot 11= 91 \ 2/3 \pi[/tex]
Hope this helps!
Answer:
[tex]Volume=\frac{1}{3} \,275\,\pi[/tex] cubic units
Notice that this answer doesn't agree with any of the first three in the list provided via the screenshot
Step-by-step explanation:
Recall the formula for the volume of a cone:
[tex]Volume=\frac{1}{3} Base\,*\,Height[/tex]
In this case the Height is 11 units, and they also give us the radius of the circular base (5 units) from which we can find the circle's base area:
[tex]Area_{circle} = \pi\,R^2\\Area_{circle}=\pi\,(5)^2\\Area_{circle}=25 \pi[/tex]
therefore the total volume becomes:
[tex]Volume=\frac{1}{3} Base\,*\,Height\\Volume=\frac{1}{3} 25\,\pi\,*\,11\\\\Volume=\frac{1}{3} \,275\,\pi[/tex]
There is more than one integer greater than 1 which leaves a reminder of1 when divided by each of the four smallest primes
Answer:
210
Complete question found at brainly(ID): 18678557 is stated below.
There is more than one integer, greater than 1, which leaves a remainder of 1 when divided by each of the four smallest primes. What is the difference between the two smallest such integers?
Step-by-step explanation:
Prime numbers are numbers that can only be divided by itself and 1
The smallest of the prime numbers we have = 2, 3, 5, 7
Since the integers greater than 1 are said to be divided by the four smallest prime numbers, we would assume the number of integers are 4 in total.
Let the integers be T
From the question:
Integer/(prime number) = quotient + (remainder/prime number)
Integer/(prime number) = Q + R/P
Let the different quotients derived from all 4 prime number = w, x, y, z
For prime 2:
T/2 = w + 1/2
T/2 - 1/2 = w
(T-1)/2 = w
T = 2w + 1
T-1 = 2w
Following the above solution
For prime 3:
T = 3x + 1
T-1 = 3x
For prime 5:
T = 5y + 1
T-1 = 5y
For prime 7:
T = 7z + 1
T-1 = 7z
T-1= T-1 = T-1 = T-1
2w = 3x = 5y = 7z
T-1 = LCM of all the prime numbers
T- 1 = 2×3×5×7
T-1 = 210
T = 210+1 = 211
T = 211
The smallest of the integer greater than 1 that leaves a remainder of 1 = 1(T-1) + 1 = 211
The next after the smallest number: 2(T-1) +1= 2(210) + 1 = 421
The two smallest number = 1(T-1) + 1 and 2(T-1) +1 respectively
The difference between the two smallest such integers = 421-211 = 210
You buy 144 inches of ribbon at 15 cents per yard and 3 1/2 pounds of tomatoes at 48 cents per pound. What is your change from a $20 bill? (SHOW YOUR WORK).
Answer:
$17.72 left
Step-by-step explanation:
144 inches = 4 yards
4(0.15) + 3.5(0.48) = 0.6 + 1.68 = $2.28 SPENT
20 - 2.28 = $17.72 left in change
HELP ASAP GIVING BRANLIST!!
Answer:
Question 1: 3 - 5 hours.
Question 2: 0 - 1 hour
Step-by-step explanation:
Question 1: As you can see in the diagram, the guy is moving really slowly and is almost stuck, therefore, it is 3 - 5 hours.
Question 2: In hours 0 - 1, you can see that the graph is the closest to vertical as it gets.
3z/10 - 4 = -6
someone help?
Answer:
[tex]z=-\frac{20}{3}[/tex]
Step-by-step explanation:
[tex]\frac{3z}{10}-4=-6\\\\\frac{3z}{10}-4+4=-6+4\\\\\frac{3z}{10}=-2\\\\\frac{10\cdot \:3z}{10}=10\left(-2\right)\\\\3z=-20\\\\\frac{3z}{3}=\frac{-20}{3}\\\\z=-\frac{20}{3}[/tex]
Best Regards!
HELP ASAP!!!The first picture is what each variables equal too
Answer:
Just replace the variables with the number
d5
c4 (uh oh)
a2
b-3
f-7
d-c = 5 - 4 = 1
1/3 - 4(ab+f)
2 x -3 = -6
-6 + -7 = -13
-13 x 4 = -52
1/3 - -52 = 1/3 + 52 =
52 1/3
Hope this helps
Step-by-step explanation:
Please answer this correctly
PLEASE ANSWER FAST !!!
What is the range of the function g for given domain ?
Answer:
The answer is B
Step-by-step explanation:
Hope this helps.. if not im sorry :(
Suppose that four microchips in a production run of sixty are defective. A sample of six is to be selected to be checked for defects. (a) How many different samples can be chosen
Answer:
50,063,860 different samples can be chosen
Step-by-step explanation:
The order in which the microchips are chosen is not important. So we use the combinations formula to solve this question.
Combinations formula:
[tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.
[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]
How many different samples can be chosen
We choose 6 microchips from a set of 60. So
[tex]C_{60,6} = \frac{60!}{6!(60-6)!} = 50063860[/tex]
50,063,860 different samples can be chosen
A consumer group was interested in comparing the operating time of cordless toothbrushes manufactured by two different companies. Group members took a random sample of 18 toothbrushes from Company A and 15 from Company B. Each was charged overnight and the number of hours of use before needing to be recharged was recorded. Company A toothbrushes operated for an average of 119.7 hours with a standard deviation of 1.74 hours; Company B toothbrushes operated for an average of 120.6 hours with a standard deviation of 1.72 hours. The 90% confidence interval is (-1.93, 0.13). The correct interpretation is:__________
A. We are 90% confident that, on average, there is no difference in operating hours between toothbrushes from Company A compared to those from Company B.
B. We are 90% confident that, on average, there is a difference in operating hours between toothbrushes from Company A compared to those from Company B.
C. We are 90% confident that, on average, the toothbrushes from Company B operate longer before needing to be recharged than the toothbrushes from Company A.
D. We are 90% confident that, on average, the toothbrushes from Company A operate longer before needing to be recharged than the toothbrushes from Company B.
Answer:
The degrees of freedom are given by:
[tex] df = n_A +n_B -2 = 18 +15-2= 31[/tex]
And the 90% confidence interval for this case is:
[tex] -1.90 \leq \mu_A -\mu_B \leq 0.13[/tex]
And for this case since the confidence interval contains the value 0 we can conclude that:
A. We are 90% confident that, on average, there is no difference in operating hours between toothbrushes from Company A compared to those from Company B.
Step-by-step explanation:
We know the following info given:
[tex] \bar X_A= 119.7[/tex] sample mean for A
[tex] s_A = 1.74[/tex] sample deviation for A
[tex] n_A = 18[/tex] sample size from A
[tex] \bar X_B= 120.6[/tex] sample mean for B
[tex] s_B = 1.72[/tex] sample deviation for B
[tex] n_B = 15[/tex] sample size from B
The degrees of freedom are given by:
[tex] df = n_A +n_B -2 = 18 +15-2= 31[/tex]
And the 90% confidence interval for this case is:
[tex] -1.90 \leq \mu_A -\mu_B \leq 0.13[/tex]
And for this case since the confidence interval contains the value 0 we can conclude that:
A. We are 90% confident that, on average, there is no difference in operating hours between toothbrushes from Company A compared to those from Company B.