Answer:
a) 0.1038 = 10.38% probability that maximum speed is at most 49 km/h
b) 0.2451 = 24.51% probability that maximum speed is at least 48 km/h
c) 0.9876 = 98.76% probability that maximum speed differs from the mean value by at most 2.5 standard deviations
Step-by-step explanation:
Normal Probability Distribution:
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score 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 p-value, we get the probability that the value of the measure is greater than X.
Mean value 46.8 km/h and standard deviation 1.75 km/h.
This means that [tex]\mu = 46.8, \sigma = 1.75[/tex]
a. What is the probability that maximum speed is at most 49 km/h?
This is the pvalue of Z when X = 49. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{49 - 46.8}{1.75}[/tex]
[tex]Z = 1.26[/tex]
[tex]Z = 1.26[/tex] has a pvalue of 0.8962
1 - 0.8962 = 0.1038
0.1038 = 10.38% probability that maximum speed is at most 49 km/h.
b. What is the probability that maximum speed is at least 48 km/h?
This is 1 subtracted by the pvalue of Z when X = 48. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{48 - 46.8}{1.75}[/tex]
[tex]Z = 0.69[/tex]
[tex]Z = 0.69[/tex] has a pvalue of 0.7549
1 - 0.7549 = 0.2451
0.2451 = 24.51% probability that maximum speed is at least 48 km/h.
c. What is the probability that maximum speed differs from the mean value by at most 2.5 standard deviations?
Zscores between Z = -2.5 and Z = 2.5, which is the pvalue of Z = 2.5 subtracted by the pvalue of Z = -2.5
Z = 2.5 has a pvalue of 0.9938
Z = -2.5 has a pvalue of 0.0062
0.9938 - 0.0062 = 0.9876
0.9876 = 98.76% probability that maximum speed differs from the mean value by at most 2.5 standard deviations
Which is bigger a population or a sample?
a - Population
b - Sample
c - They are both the same
Which shape is the base of the pyramid shown below?
A triangle
B square
Answer:
B. it's a square pyramid so the base is a square.
Step-by-step explanation:
6/x=2x+4/5 multiply each side by the common denominator to find the quadratic equation equivalent to this equation
9514 1404 393
Answer:
C. 2x² +4x -30 = 0
Step-by-step explanation:
This is what you get when you follow the instructions.
[tex]\dfrac{6}{x}=\dfrac{2x+4}{5}\qquad\text{given}\\\\\dfrac{6(5x)}{x}=\dfrac{(5x)(2x+4)}{5}\qquad\text{multiply by the common denominator $5x$}\\\\30=x(2x+4)\qquad\text{cancel common factors}\\\\30=2x^2+4x\qquad\text{eliminate parentheses}\\\\\boxed{2x^2+4x-30=0}\qquad\text{subtract 30}[/tex]
Please help me with this ASAP ASAP please please help
Answer:
Step-by-step explanation:
Base perimeter: 4 x 2 x π = 8π
LA = 8π x 6 = 48π
Base area = 4^2π = 16π
SA = 16π x 2 + 48π = 80π
V= 16π x 6 = 96π
Find the slope of each line (no links I’ll report)
Answer:
Slope = ⁵/7
Step-by-step explanation:
Slope (m) = change in y / change in x
Using two points on the graph, (-4, -4) and (3, 1),
Slope (m) = (1 - (-4))/(3 - (-4)) = 5/7
Slope (m) of the line = 5/7
A student records the repair cost for 22 randomly selected dryers. A sample mean of $98.78 and standard deviation of $15.49 are subsequently computed. Determine the 95% confidence interval for the mean repair cost for the dryers. Assume the population is approximately normal. Step 1 of 2 : Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places.
Answer:
The critical value that should be used is T = 2.0796.
The 95% confidence interval for the mean repair cost for the dryers is between $91.912 and $105.648.
Step-by-step explanation:
We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 22 - 1 = 21
95% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 21 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.95}{2} = 0.975[/tex]. So we have T = 2.0796, which is the critical value that should be used.
The margin of error is:
[tex]M = T\frac{s}{\sqrt{n}} = 2.0796\frac{15.49}{\sqrt{22}} = 6.868[/tex]
In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 98.78 - 6.868 = $91.912
The upper end of the interval is the sample mean added to M. So it is 98.78 + 6.868 = $105.648
The 95% confidence interval for the mean repair cost for the dryers is between $91.912 and $105.648.
Solve using the tangent formula(real answers only please)
9514 1404 393
Answer:
21.07
Step-by-step explanation:
The tangent ratio is ...
Tan = Opposite/Adjacent
For the given values, this is ...
tan(36°) = x/29
Solving for x, we have ...
x = 29·tan(36°)
x ≈ 21.07
If x =10 what is x over 2 plus 3x ??
Answer:
35
Step-by-step explanation:
Substitute x in the equation for 10
x/2 = 10/2
+ 3x = + 3(10)
10/2 = 5
+ 3(10) = + 30
5 + 30 = 35
Simplify 4x + 3x² + x² - 3x
Answer:
[tex]x + {4x}^{2} [/tex]
Step-by-step explanation:
simplify by combining like terms
4x - 3x = x
[tex]3x ^{2} + {x}^{2} = {4x}^{2} [/tex]
we're left with
[tex]x + {4x}^{2} [/tex]
Answer:
4x²+x
Step-by-step explanation:
4x-3x+3x²+x²
4x minus 3x is x and 3x² +x² is 4x²
therefore,
4x²+x
3 1/7 x 10 answer plz
Answer:
31.43
Step-by-step explanation:
3 1/7 = 3.14285714285
3 1/7 x 10 = 31.4285714286 which is about 31.43
Answer:
31 [tex]\frac{3}{7}[/tex]
Step-by-step explanation:
[tex]\frac{22}{7}[/tex]×[tex]\frac{10}{1}[/tex]
[tex]\frac{220}{7}[/tex]
31 [tex]\frac{3}{7}[/tex]
Answer choices
15
18
20
30
Please help no links I will report
Answer:
18 people.
Step-by-step explanation:
thirty percent of 60 is 18
write the following comparison as a ratio reduced to lowest terms.
94 hours to 8 days
Answer:
11.75:1
Step-by-step explanation:
alrighty right, more unit rates, so we have to get that 8 down to 1. How are we gonna do that? By dividing it by 8. And if we divide one side by 8, we also have to divide the other side:
8 ÷ 8 = 1
94 ÷ 8 = 11.75
So 94 hours to 8 days in lowest terms is 11.75 hours to 1 day
What Are the missing numbers?
Answer:
[tex] y = -\frac{3}{2}x + 12 [/tex]
Step-by-step explanation:
The missing numbers represent the slope/rate of change (m) and y-intercept (b) of the table of values given.
✔️Let's find slope (m) using any two given pairs of values, say (2, 9) and (4, 6):
Slope (m) = change in y/change in x
= (6 - 9)/(4 - 2)
= -3/2
m = -³/2
✔️Find b by substituting (x, y) = (2, 9), and m = -³/2 into y = mx + b
Thus,
9 = -³/2(2) + b
9 = -3 + b
9 + 3 = b
b = 12
The missing numbers are -³/2 and 12.
Which will give us:
[tex] y = -\frac{3}{2}x + 12 [/tex]
peggy drives for 3 hours at an average speed of 61 miles per hour. Then when she crosses over into the next state she is able to drive the next 2.5 hours at an average speed of 72 miles per hour.
what was her average speed for the entire trip?
Answer:
65 miles per hour
The price of a necklace was increased by 10% to £121.
What was the price before the increase?
Answer:
£108.90
Step-by-step explanation:
[tex]121 \times 10\% \\ = 121 \times 0.10 \\ = 108.90[/tex]
PLEASE HELP !! ILL GIVE BRAINLIEST !!
Answer:
-8x+8=-6x+20 and x= -6
Step-by-step explanation:
Reason to equation:
This image shows alternative interior angles.
Alternative interior angles are congruent to each other.
How to find x:
-8x+8=-6x+20
We subtract 8 from both sides
-8x=-6x+12
We add 6x to both sides
-2x=12
We divided -2 from both sides
-2x/-2x = 12/2
Leaving us with x=-6
PLEASE HELP NO LINK ANSWER I WILL GIVE BRAINLY THING BOTH QUESTIONS PLEASE
Answer: 33. Glucose 34. stomach
Step-by-step explanation:
A scale drawing used for the model of a building is 1 inch = 150 feet. How tall is the building if the scale model is 6 inches tall?
Answer:
900
Step-by-step explanation:
1 inch/150 feet x 6 inch/x feet
cross multiply
1x=900
In triangle ABC, the length of side AB is 19 inches and the length of side BC is 28 inches. Which of the following could be the
length of side AC?
Answer:
43 inches
Step-by-step explanation:
The quotient of a numberpo, and five
Please help
Answer:
x over 5 or x divided by 5
Step-by-step explanation:
x over 5 : [tex]\frac{x}{5}[/tex]
x divided by 5 : x ÷ 5
Find [tex]a_{1}[/tex] in a geometric series for which [tex]S_{n}[/tex] = 189, r = [tex]\frac{1}{2}[/tex], and [tex]a_{n}[/tex] = 3.
Answer:
[tex] \displaystyle a_{1} = 108[/tex]
Step-by-step explanation:
we are given
the sum,common difference and nth term of a geometric sequence
we want to figure out the first term
recall geometric sequence
[tex] \displaystyle S_{ \text{n}} = \frac{ a_{1}(1 - {r}^{n} )}{1 - r} [/tex]
we are given that
[tex]S_n=189[/tex][tex]r=\dfrac{1}{2}[/tex][tex]n=3[/tex]thus substitute:
[tex] \displaystyle 189= \frac{ a_{1}(1 - {( \frac{1}{2} )}^{3} )}{1 - \frac{1}{2} } [/tex]
to figure out [tex]a_1[/tex] we need to figure out the equation
simplify denominator:
[tex] \displaystyle \frac{ a_{1}(1 - {( \frac{1}{2} )}^{3} )}{ \dfrac{1}{2} } = 189[/tex]
simplify square:
[tex] \displaystyle \frac{ a_{1}(1 - {( \frac{1}{8} )}^{} )}{ \dfrac{1}{2} } = 189[/tex]
simplify substraction:
[tex] \displaystyle \frac{ a_{1} (\frac{7}{8} )}{ \frac{1}{2} } = 189[/tex]
simplify complex fraction:
[tex] \displaystyle a_{1} (\frac{7}{8} ) \div { \frac{1}{2} } = 189[/tex]
calculate reciprocal:
[tex] \displaystyle a_{1} \frac{7}{8} \times 2 = 189[/tex]
reduce fraction:
[tex] \displaystyle a_{1} \frac{7}{4} \ = 189[/tex]
multiply both sides by 4/7:
[tex] \displaystyle a_{1} \frac{7}{4} \times \frac{4}{7} \ = 189 \times \frac{4}{7} [/tex]
reduce fraction:
[tex] \displaystyle a_{1} = 27\times 4[/tex]
simplify multiplication:
[tex] \displaystyle a_{1} = 108[/tex]
hence,
[tex] \displaystyle a_{1} = 108[/tex]
In rectangle ABCD,If EC=13 find BD
Answer:
[tex]BD = 26\\[/tex]
Step-by-step explanation:
Given
[tex]EC = 13[/tex]
Required
Find [tex]BD[/tex]
In the given rectangle.
AC and BD are the diagonals.
This implies that:
[tex]AC = BD[/tex]
AC is calculated as:
[tex]AC = AE + EC[/tex]
Where
[tex]AE = EC[/tex]
So:
[tex]AC = EC + EC[/tex]
[tex]AC = 13+13[/tex]
[tex]AC = 26[/tex]
Recall that: [tex]AC = BD[/tex]
[tex]BD = 26\\[/tex]
someone please answer this
Answer:
9.4m is the answer.
Step-by-step explanation:
a = 8m
b = 5m
c = ?
According to the Pythagoras theorem,
a² + b² = c²
8² + 5² = c²
64 + 25 = c²
89 = c²
c = 9.433
Rounding off,
c = 9.4m
Which answer choice represents a person burning 45
calories by climbing 9 flights of stairs?
F
Number of Flights of
Stairs Climbed, f
Number of Calories
Burned, c
G.
c=f+5, where c represents the number of
calories burned and f represents the number of
flights of stairs climbed.
1
5
3
15
5
25
7
35
J
A person who climbs 5 flights of stairs will
burn 1 calorie
90
22
Need
Heln2
During a winter storm, the amount of snowfall was recorded in 5 different locations. All measurements have been rounded to the nearest 1/2 inch. How many times as great is the amount of snow at the location that received the most snow as the location that received the least snow?
Answer:
Most snow- 3 1/2 inch least snow, 1/2 inch
Step-by-step explanation:
If ∠1 and ∠2 are vertical angles and m∠2 = 108°, find m∠1.
Answer:
angle 1 = 108°
Step-by-step explanation:
because angle 1 and angle 2 are vertical angles and vertical angles are equal.
The mean number of points in 1977 was 1189 points with standard deviation of 397 points. With a roughly normal distribution, what percent of performances would fall between 395 and 1983 points?
Your answer
A. 100%
B. 68%
C. 95%
D.99.7%
Answer:
C. 95%
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
Approximately 68% of the measures are within 1 standard deviation of the mean.
Approximately 95% of the measures are within 2 standard deviations of the mean.
Approximately 99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean of 1189 points, standard deviation of 397 points.
Percentage between 395 and 1983 points?
395 = 1189 - 2*397
1983 = 1189 + 2*397
So within 2 standard deviations of the mean, which by the Empirical Rule is approximately 95%, and the answer is option C.
Your marketing team has conducted two focus group sessions to evaluate a new product design. The first focus group consisted of teenagers and resulted in four out of five liking the new product. The second group was made up of parents of young children. Only one out of five people in this group said they liked the same new product as the teens. With 90% confidence (Z = 1.64), can you say that there is a difference between the views of these two populations? Please show your calculations, use 2 decimal places in your calculation answer, and justify your answer regarding differences.
Answer:
Since the calculated Z falls in the critical region therefore the null hypothesis is rejected and concluded that there is a difference between the views of these two populations.
Step-by-step explanation:
1) Formulate the hypotheses:
H0 : p1=p2
Ha: p1 ≠ p2
2) The significance level is chosen at ∝= 0.1
3) The critical region is Z∝/2 ≥ ± 1.645
4) The test statistic under H0 is
Z = p1^- p2^/ √p^q^( 1/n1 + 1/n2)
p1^= proportion of of teenagers liking the new product.
p2^ = proportion of of parents of young children liking the new product.
p1^= 4/5
p2^= 1/5
p^= 5(0.8) + 5(0.2)/5+5= 4+1/10= 0.5
q^= 0.5
Thus
Z= p1^- p2^/ √p^q^( 1/n1 + 1/n2)
z= 0.8-0.2/√0.5*0.5( 1/5 + 1/5)
z= 0.6/ 0.316227
z= 1.897
5) Conclusion:
Since the calculated Z falls in the critical region therefore the null hypothesis is rejected and concluded that there is a difference between the views of these two populations.
Sally's savings account has $238 and she is withdrawing (taking money out) $17 each week to put gas in her car. How much money will Sally have after 5 weeks?
Answer:
$153
Step-by-step explanation:
Which expression is the simplest form of 2(4x + y) + 3(x - 6y) + x2?
O A. x2 + 11x-17y
B. x2 + 11x – 4y
C. x2 + 9x- 17y
O D. x2 + 11x-16y
Answer:
x² + 11x-16y
Step-by-step explanation:
The given equation is :
[tex]2(4x + y) + 3(x - 6y) + x^2[/tex]
It can be simplified as follows :
[tex]2(4x + y) + 3(x - 6y) + x^2\\\\=2(4x)+2y+3x-3(6y)+x^2\\\\=8x+2y+3x-18y+x^2\\\\=11x-16y+x^2[/tex]
So, the correct option is (d) i.e. x² + 11x-16y.