9. Find the mean of the following data :
Х
8
10
12
20
16
F
2
3
7
2
5​

Answer:

6.14 inches

Step-by-step explanation:

The one side of the dollar bill is 6.14 inch. The 6.14 inches of the dollar approximates the 156.1 mm. When Malia measures the longer side of a dollar bill from her rule it will be approximately 6.14 inches in length. The ruler normally has inches and cm sides. Very few rulers have mm scales. The most probable scale that malia would have measure is in inches.

Answer: 7

Step-by-step explanation:

Answer :

It Is 7 On Khan Academy

◊ YusuCr ◊

:)

Answer:

0.30924

Approximately ≈ 0.3092

Step-by-step explanation:

To solve for this question, we use the formula:

z = (x - μ)/σ

where x is the raw score

μ is the sample mean

σ is the sample standard deviation.

From the question,

x is the raw score = 260

μ is the sample mean = population standard deviation = 258

σ is the sample standard deviation

= σ/√N

N = 76 samples

σ = Population standard deviation

= 35/√76

= 4.0146919966

Hence,

z = (x - μ)/σ

= 260 - 258/ 4.0146919966

= 0.4981702212

Approximately = 0.498

We find the Probability using z score table for normal distribution

P(x = z) = P( x = 260)

= P( z = 0.498)

= 0.69076

The probability that a random customer will have more than $260 in his or her wallet is calculated as:

P(x>Z) = 1 - P( z = 0.498)

P(x>Z) = 1 - 0.69076

P(x>Z) = 0.30924

Approximately ≈ 0.3092

Answer:

Step-by-step explanation:

vertical stretching / shrinking has the following transformation.

f(x) -> a * f(x)

when a >  1, it is stretching

when 0< a < 1, it is shrinking.

when  -1 < a < 0, it is shringking + reflection about the x-axis

when a < -1, it is stretching + reflection about the x axis.

Here it is simple shrinking, so 0 < a < 1.

I expect the answer choice to show (1/3) f(x).

However, if the question plays with the words

"shrink by a factor of 1/3" to actually mean a "stretching by a factor of three", then B is the answer (stretch by a factor of three).

Answer: The multiplicative inverse of – 1 in the set {-1,1} is -1.

Step-by-step explanation:

In algebra, the multiplicative inverse of a number(x) is a number (say y) such that

[tex]x\times y=1[/tex]  [product of a number and its inverse =1]

if x= -1, then

[tex]-1\times y=1\Rightarrow\ y=-1[/tex]

That means , the multiplicative inverse of -1 is -1 itself.

Hence, the multiplicative inverse of – 1 in the set {-1,1} is -1.

Answer:

D

Step-by-step explanation:

The ratio of yellow paint to blue paint is 4:3. We can make the largest amount of green paint by using all of the 20 quarts of yellow paint so we have to solve for x in 4:3 = 20:x, since 4 * 5 = 20, 3 * 5 = x so we use 15 qts of blue paint, therefore we will have 20 + 15 = 35 qts of green paint.

Answer:

D

Step-by-step explanation:

Answer:

3 miles

Step-by-step explanation:

5 + m=8

Subtract 5 from each side

5-5 + m=8-5

m = 3

She needs to swim 3 more miles

Answer:

Yelena needs to swim 3 more miles

Step-by-step explanation:

You need to solve for the variable "m", which represents the miles. Based on the information, Yelena swam 5 miles and she needs to swim 8. Solve:

[tex]5+m=8[/tex]

To find the value of m, you need to isolate it on one side of the equation. To do this, you need to get the 8 and 5 on the same side of the equal operation. For this, you need to use reverse operations. This undoes the value from one side and does the same on the other, keeping the equation balanced. Since we have a "positive 5", we take the opposite, which would be a "negative 5". So subtract 5 from both sides of the equation:

[tex]5-5+m=8-5[/tex]

Simplify. The 5's cancel each other out, leaving 0. 8-5 is 3:

[tex]m=3[/tex]

The total miles left that Yelena needs to swim is 3 miles.

:Done

Answer:

Both angle measures and segment lengths.

Step-by-step explanation:

An angle is a shape formed by two rays that meets at a point. The angle is measured by degrees. The angle is formed by the sides of an angle which shares the common endpoint called the vertex. The line is horizontal stretch with a vertical line PQ. It will measure the angle and segments lengths.

Answer:

neither angle measures nor segment lines

Answer:

The answer is

Step-by-step explanation:

11a³b - 24a²b² - 27ab³

To factor the expression

First factor ab out

That's

ab ( 11a² - 24ab - 27b²)

Factor the terms in the bracket

Write - 24ab as a difference

That's

ab ( 11a² + 9ab - 33ab - 27b²)

Factor out a from the expression

ab [ a( 11a + 9b) - 33ab - 27b²) ]

Factor -3b from the expression

That's

ab [ a( 11a + 9b) - 3b( 11a + 9b) ]

Factor out 11a + 9b from the expression

We have the final answer as

Hope this helps you

Answer: 669

Step-by-step explanation:

Given, In a Gallup poll of randomly selected​ adults, 66% said that they worry about identity theft.

i.e. The proportion of adults said that they worry about identity theft. (p) = 0.66

Sample size : n= 1013

Then , Mean for the sampling distribution of sample proportion  = np

= (1013) × (0.66)

= 668.58 ≈ 669  [Round to the nearest whole number]

Hence, the mean of those who do not worry about identify theft is closest to​ 669 .

Step-by-step explanation:

Find the z-score.

z = (x − μ) / σ

z = (109.8 − 106.9) / 14.5

z = 0.2

Use a chart or calculator to find the probability.

P(Z < 0.2) = 0.5793

Find the mean and standard deviation of the sampling distribution.

μ = 106.9

σ = 14.5 / √20 = 3.242

Find the z-score.

z = (x − μ) / σ

z = (109.8 − 106.9) / 3.242

z = 0.894

Use a calculator to find the probability.

P(Z < 0.894) = 0.8145

Complete Question

A research center claims that ​30% of adults in a certain country would travel into space on a commercial flight if they could afford it. In a random sample of 700 adults in that​ country, ​34% say that they would travel into space on a commercial flight if they could afford it. At ​, is there enough evidence to reject the research center's claim

Answer:

Yes there is  sufficient evidence to reject the research center's claim.

Step-by-step explanation:

From the question we are told that

     The population proportion is  p = 0.30

      The sample proportion is  [tex]\r p = 0.34[/tex]

       The  sample size is  n = 700

The null hypothesis is  [tex]H_o : p = 0.30[/tex]

 The  alternative hypothesis is  [tex]H_a : p \ne 0.30[/tex]

Here we are going to be making use of  level of significance  =  0.05 to carry out this test

Now we will obtain the critical value of  [tex]Z_{\alpha }[/tex] from the normal distribution table , the value is  [tex]Z_{\alpha } = 1.645[/tex]

 Generally the test statistics is mathematically represented as

            [tex]t = \frac{ \r p - p }{ \sqrt{ \frac{ p (1-p)}{n} } }[/tex]

substituting values

              [tex]t = \frac{ 0.34 - 0.30 }{ \sqrt{ \frac{ 0.30 (1-0.30 )}{ 700} } }[/tex]

              [tex]t = 2.31[/tex]

Looking at the values of t  and  [tex]Z_{\alpha }[/tex] we see that [tex]t > Z_{\alpha }[/tex] hence the null hypothesis is rejected

 Thus we can conclude that there is  sufficient evidence to reject the research center's claim.

Answer:

x = -2.6, x = 2.6

Step-by-step explanation:

The graph crosses the x-axis at approximately 2.6 and -2.6.

The required approximate solution of the function graphed is x = -2.6 and 2.6.

Given that,
A graph of a function is plotted, and the solution of the function is to be determined.

Functions are the relationship between sets of values. e g y=f(x), for every value of x there is its exists in a set of y. x is the independent variable while Y is the dependent variable.

The graph is a demonstration of curves that gives the relationship between the x and y-axis.

Here, the solution of the function is that value of x where the function terminates to zero, So the given curve terminates to zero at two places at x = -2.6 and x = 2.6 from the observation of the graph.

Thus, the required approximate solution of the function graphed is x = -2.6 and 2.6.

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Answer:

B = 34.2°

C = 105.8°

c = 12.0 units

Step-by-step Explanation:

Given:

A = 40°

a = 8

b = 7

Required:

Find B, C, and c.

SOLUTION:

Using the Law of Sines, find <B:

[tex] \frac{sin(A)}{a} = \frac{sin(B)}{b} [/tex]

[tex] \frac{sin(40)}{8} = \frac{sin(B)}{7} [/tex]

Multiply both sides by 7

[tex] \frac{sin(40)}{8}*7 = \frac{sin(B)}{7}*7 [/tex]

[tex] \frac{sin(40)*7}{8} = sin(B) [/tex]

[tex] 0.5624 = sin(B) [/tex]

[tex] B = sin^{-1}(0.5624) [/tex]

[tex] B = 34.2 [/tex] (to nearest tenth).

Find <C:

C = 180 - (34.2+40°) (sum of angles in a triangle)

C = 180 - 74.2 = 105.8°

Using the Law of Sines, find c.

[tex] \frac{c}{sin(C)} = \frac{b}{sin(B)} [/tex]

[tex]\frac{c}{sin(105.8)} = \frac{7}{sin(34.2)}[/tex]

Multiply both sides by sin(105.8)

[tex]\frac{c}{sin(105.8)}*sin(105.8) = \frac{7}{sin(34.2)}*sin(105.8)[/tex]

[tex] c = \frac{7*sin(105.8)}{sin(34.2)} [/tex]

[tex] c = 12.0 [/tex]

Answer:

40 mL of 10% acid

80 mL of 25% acid

Step-by-step explanation:

x = volume of 10% acid solution

y = volume of 25% acid solution

Total volume is:

x + y = 120

Total amount of acid is:

0.10 x + 0.25 y = 0.20 (120)

Solve by substitution.

0.10 x + 0.25 (120 − x) = 0.20 (120)

0.10 x + 30 − 0.25 x = 24

0.15 x = 6

x = 40

y = 80

Answer:

approximately x = 38

Step-by-step explanation:

The maximum profit is the vertex of the profit graph parabola. The maximum occurs at approximately x = 38.

The solution is x = 38

The location on the profit function parabola where the profit from sales of the phone cases is a maximum is given by x = 38

A Parabola, open curve, a conic section produced by the intersection of a right circular cone and a plane parallel to an element of the cone. A parabola is a plane curve generated by a point moving so that its distance from a fixed point is equal to its distance from a fixed line

The equation of the parabola is given by

( x - h )² = 4p ( y - k )

where ( h , k ) is the vertex and ( h , k + p ) is the focus

y is the directrix and y = k – p

The equation of the parabola is also given by the equation

y = ax² + bx + c

where a , b , and c are the three coefficients and the parabola is uniquely identified

Given data ,

Let the revenue, cost, and profit functions for a line of cell phone cases be given as two parabolic functions R ( x ) and P ( x )

The maximum profit is given by the parabolic function R ( x )

The profit is represented by = y

The price per phone is represented by = x

Now , when y is maximum ,

The value of y = $ 2,250,000

The value of x when y = $ 2,250,000 is x = 38

So , the value of x from the parabola where profit is maximum is x = 38

Therefore,  the value of x = 38

Hence , the value of x from the function is x = 38

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Answer:

continuous

Step-by-step explanation:

A quantity like temperature is a continuous random variable. A continuous random variable is different from a discrete random variable because it can take on many values infinitely.

From the question, measuring the Temperature in degrees can take on many different values because there are an uncountable number of possible temperatures that could be taken.

Answer:

6/50

Step-by-step explanation:

There are 50 tiles

6 purple

18 pink

26 orange

P( purple) = purple/ total

                = 6/50

Answer:

Perimeter of ABCD = 36 ft

Step-by-step explanation:

Given:

A (1,7)

B (7,7)

C (7,1)

D (1,1)

Find:

Perimeter of ABCD

Computation:

Distance between two point = √(x1-x2)² + (y1-y2)²

So,

AB = √(1-7)²+(7-7)²

AB = 6 ft

BC = √(7-7)²+(7-1)²

BC = 6 ft

CD = √(7-1)²+(1-1)²

CD = 6 ft

DA = √(1-1)²+(1-7)²

DA = 6 ft

Perimeter of ABCD = AB + BC + CD + DA

Perimeter of ABCD = 6 + 6 + 6 +6

Perimeter of ABCD = 36 ft

The perimeter of the plot is the sum of side length of the plot of land.

The perimeter of the plot is 24 feet.

Represent the vertices as follows:

[tex]W = (1,7)[/tex]

[tex]X = (7,7)[/tex]

[tex]Y = (7,1)[/tex]

[tex]Z = (1,1)[/tex]

First, we calculate the side length using the following distance formula:

[tex]d = \sqrt{(x_1 - x_2)^2 + (y_1 - y_2)^2}[/tex]

So, we have:

[tex]WX = \sqrt{(1- 7)^2 + (7- 7)^2} = \sqrt{36} = 6[/tex]

[tex]XY = \sqrt{(7- 7)^2 + (7- 1)^2} = \sqrt{36} = 6[/tex]

[tex]YZ = \sqrt{(7- 1)^2 + (1- 1)^2} = \sqrt{36} = 6[/tex]

[tex]ZW = \sqrt{(1- 1)^2 + (1- 7)^2} = \sqrt{36} = 6[/tex]

The perimeter (P) is then calculated as follows:

[tex]P = WX + XY + YZ + ZW[/tex]

So, we have:

[tex]P = 6 + 6 + 6 + 6[/tex]

[tex]P = 24[/tex]

Hence, the perimeter of the plot of land is 24 feet.

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Answer: the distance is  3.49 units

Step-by-step explanation:

There are some ways to find the exact distance, i will calculate the distance in rectangular coordinates.

When we have a point (R, θ) in polar coordinates, we can transform it into rectangular coordinates as:

x = R*cos(θ)

y = R*sin(θ)

Then we have:

(7,217pi/180 )

R = 7

θ = (217/180)*pi

x = 7*cos( (217/180)*pi) = -5.59

y = 7*sin( (217/180)*pi) = -4.21

So this point is (-5.59, -4.21) in rectangular coordinates.

And the other point is  (5,-23pi/36 )

R = 5

θ = -(23/36)*pi

x = 5*cos(  -(23/36)*pi ) = -2.11

y = 5*sin(  -(23/36)*pi ) = -4.53

So this point is (-2.11, - 4.53)

Then the point distance between those points is:

D = I (-2.11, -4.53) - (-5.59, -4.21) I

D = I (-2.11 + 5.59, -4.53 + 4.21) I

D = I (3.48, -0.32) I = √( (3.48)^2 + (-0.32)^2) =  3.49

The statement is false. A sampling distribution is normal if either n > 30 or the population is normal.

==========================================

Explanation:

If the underlying population is normally distributed, then so is the sample distribution (such as the distribution of sample means, aka xbar distribution).

Even if the population isn't normally distributed, the xbar distribution is approximately normal if n > 30 due to the central limit theorem. Some textbooks may use a higher value than 30, but after some threshold is met is when the xbar distribution is effectively "normal".

Choice A is close, but is missing the part about the population being normal. If we know the population is normal, then n > 30 doesn't have to be required.

Answer:

Step-by-step explanation:

[tex] \sf{ - 7y = - 91}[/tex]

Divide both sides of the equation by -7

⇒[tex] \sf{ \frac{ - 7y}{ - 7} = \frac{ - 91}{ - 7} }[/tex]

Calculate

⇒[tex] \sf{y = 13}[/tex]

Hope I helped!

Best regards!!

Answer:

[tex] \boxed{\sf y = 13} [/tex]

Step-by-step explanation:

Solve for y:

[tex] \sf \implies - 7y = - 91[/tex]

Divide both sides of -7y = -91 by -7:

[tex] \sf \implies \frac{ - 7y}{ - 7} = \frac{ - 91}{ - 7} [/tex]

[tex] \sf \frac{ - 7}{ - 7} = 1 : [/tex]

[tex] \sf \implies y = \frac{ - 91}{ - 7} [/tex]

[tex] \sf \implies y = \frac{ \cancel{ - 7} \times 13}{ \cancel{ - 7}} [/tex]

[tex] \sf \implies y = 13[/tex]

Answer:

I only know two right answers.

A: The center of dilation is point C.

C: It is an enlargement.

E: The scale factor is 2/5.

Step-by-step explanation:

These two answers are correct because When you look in the center you see a C.

You tell if it is a reduction because the pre image is small but the image is big.

The center of dilation is point C.

It is an enlargement.

The scale factor is 2/5

The correct options are D, F, H.

Resizing an item uses a transformation called dilation. Dilation is used to enlarge or shorten the structures. The result of this transformation is an image with the same shape as the original. However, there is a variation in the shape's size. The initial form should be stretched or contracted during a dilatation.

Given:

The transformation of the figure is dilation.

The figure is given in the attached image.

From the diagram:

The center of dilation is point C.

It is an enlargement.

The scale factor is 2/5

Therefore, all the correct statements are given above.

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Answer:

[tex]\displaystyle \oint_C {3y \, dx + 2x \, dy} = \boxed{\bold{2}}[/tex]

General Formulas and Concepts:
Calculus

Differentiation

Derivative Property [Multiplied Constant]:
[tex]\displaystyle (cu)' = cu'[/tex]
Derivative Rule [Basic Power Rule]:

Integration

Integration Rule [Fundamental Theorem of Calculus 1]:
[tex]\displaystyle \int\limits^b_a {f(x)} \, dx = F(b) - F(a)[/tex]

Integration Property [Multiplied Constant]:
[tex]\displaystyle \int {cf(x)} \, dx = c \int {f(x)} \, dx[/tex]

Multivariable Calculus

Partial Derivatives

Vector Calculus

Circulation Density:
[tex]\displaystyle F = M \hat{\i} + N \hat{\j} \rightarrow \text{curl} \ \bold{F} \cdot \bold{k} = \frac{\partial N}{\partial x} - \frac{\partial M}{\partial y}[/tex]

Green's Theorem [Circulation Curl/Tangential Form]:
[tex]\displaystyle \oint_C {F \cdot T} \, ds = \oint_C {M \, dx + N \, dy} = \iint_R {\bigg( \frac{\partial N}{\partial x} - \frac{\partial M}{\partial y} \bigg)} \, dx \, dy[/tex]

Step-by-step explanation:

Step 1: Define

Identify given.

[tex]\displaystyle \oint_C {3y \, dx + 2x \, dy}[/tex]

[tex]\displaystyle \text{Region:} \ \left \{ {{0 \leq x \leq \pi} \atop {0 \leq y \leq \sin x}} \right.[/tex]

Step 2: Integrate Pt. 1

Step 3: Integrate Pt. 2

We can evaluate the Green's Theorem double integral we found using basic integration techniques listed above:
[tex]\displaystyle \begin{aligned}\oint_C {3y \, dx + 2x \, dy} & = - \int\limits^{\pi}_0 \int\limits^{\sin x}_0 {} \, dy \, dx \\& = - \int\limits^{\pi}_0 {y \bigg| \limits^{y = \sin x}_{y = 0}} \, dx \\& = - \int\limits^{\pi}_0 {\sin x} \, dx \\& = \cos x \bigg| \limits^{x = \pi}_{x = 0} \\& = \boxed{\bold{2}}\end{aligned}[/tex]

∴ we have evaluated the line integral using Green's Theorem.

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Topic: Multivariable Calculus

Unit: Green's Theorem and Surfaces

Answer:

Sum : 65

Step-by-step explanation:

In this notation, n is our starting value, and hence we start at 3 and go to 7. Given the set of values : { 3, 4, 5, 6, 7 }, we can substitute in our expression " 4n - 7 " for n and solve. The sum of these values is our solution.

4( 3 ) - 7 = 12 - 7 = 5,

4( 4 ) - 7 = 16 - 7 = 9,

4( 5 ) - 7 = 20 - 7 = 13,

Our remaining values for n = 6 and n = 7 must then be 17 and 21. This is predictable as we have an arithmetic series here, the common difference being 4. As you can see 9 - 5 = 4, 13 - 9 = 4, 17 - 13 = 4, 21 - 17 = 4.

Therefore we have the series { 5, 9, 13, 17, 21 }. This adds to an answer of 65.

Answer:

These are the first 100 digits of pi: 3.14159 26535 89793 23846 26433 83279 50288 41971 69399 37510 58209 74944 59230 78164 06286 20899 86280 34825 34211 7067

Step-by-step explanation:

Pi goes on continuously forever, so this is a reduced version, by including the first 100 digits.

Answer:

There is not sufficient evidence to support a claim of linear correlation between the two variables.

Step-by-step explanation:

(a)

The scatter plot for the provided data is attached below.

(b)

The hypothesis to test significance of linear correlation between the two variables is:

H₀: There is no linear correlation between the two variables, i.e. ρ = 0.

Hₐ: There is a significant linear correlation between the two variables, i.e. ρ ≠ 0.

(c)

Use the Excel function: =CORREL(array1, array2) to compute the correlation coefficient, r.

The correlation coefficient between the number of internet users and the award winners is,

r = 0.786.

The test statistic value is:

[tex]t=r\sqrt{\frac{n-2}{1-r^{2}}}[/tex]

  [tex]=0.786\times\sqrt{\frac{6-2}{1-(0.786)^{2}}}\\\\=2.5427\\\\\approx 2.54[/tex]

Thus, the test statistic is 2.54.

(d)

The degrees of freedom is,

df = n - 2  

  = 6 - 2

  = 4

Compute the p-value as follows:

[tex]p-value=2\cdot P(t_{n-2}<2.54)=2\times 0.032=0.064[/tex]

*Use a t-table.

p-value = 0.064 > α = 0.05

The null hypothesis will not be rejected.

Thus, it can be concluded that there is not sufficient evidence to support a claim of linear correlation between the two variables.

Answer:

Below

Step-by-step explanation:

Let T be triangle, C the circle and S the square.

● T + T + T = 30

● 3T = 30

Divide both sides by 3

● 3T/3 = 30/3

● T = 10

So the triangle has a value of 10.

●30 T + C + C = 20C + S + S = 13T +C ×S/2

Add like terms together

●30 T + 2C = 20C +2S= 13T + C×S/2

Replace T by its value (T=10)

● 300 + 2C = 20C + 2S = 130 + C×S/2

Take only this part 20C + 2S = 130 + C × S/2

● 20C + 2S = 130 + C×S/2 (1)

Take this part (300+2C = 20C+2S) and express S in function of C

● 20C + 2S = 300 + 2C

Divide everything by 2 to make easier

● 10 C + S = 150+ C

● S = 150+C-10C

● S = 150-9C

Replace S by (5-9C) in (1)

● 20C + 2S = 130 + C×S/2

● 20C + 2(150-9C) = 130 +C× (150-9C)/2

● 20C + 300-18C= 130 + C×(75-4.5C)

● 2C + 300 = 130 + 75 -4.5C^2

● 2C +300-130 = 75C - 4.5C^2

● 2C -75C + 170 = -4.5C^2

● -73C + 170 = -4.5C^2

Multiply all the expression by -1

● -4.5C^2 +73C+ 170= 0

This is a quadratic equation, so we will use the discriminant method.

Let Y be the discriminant

● Y = b^2-4ac

● b = 73

● a = -4.5

● c = 170

● Y = 73^2 - 4×(-4.5)×170= 8389

So the equation has two solutions:

● C = (-b +/- √Y) /2a

√Y is approximatively 92

● C = (-73 + / - 92 )/ -9

● C = 18.34 or C = -2.11

Approximatively

● C = 18 or C = -2

■■■■■■■■■■■■■■■■■■■■■■■■■

● if C = 18

30T + 2C = 300 + 36 = 336

● if C = -2

30T + 2C = 300-4 = 296

Answer:

3

Step-by-step explanation:

z - 2x

--------

y

Let x = 3  y = -4 and z  =-6

-6 - 2(3)

--------

-4

-6 -6

---------

-4

-12

-----

-4

3

Answer:

3

Step-by-step explanation:

To solve this, we need to plug in each of the numbers to the equation.

x = 3, y = - 4, z = - 6

[tex]\frac{z-2x}{y} = \frac{-6-2(3)}{-4}[/tex]

Let's solve the parenthesis first. - 2 * 3 = - 6.

[tex]\frac{-6-6}{-4}[/tex]

We then subtract -6 - 6.

[tex]\frac{-12}{-4}[/tex]

Then, we divide (cancel out the negatives).

[tex]-12 / -4 =3[/tex]

Our final answer is 3. Hope this helps!

Answer:

The mean commute time in the U.S. is less than half an hour.

Step-by-step explanation:

In this case we need to test whether the mean commute time in the U.S. is less than half an hour.

The information provided is:

 [tex]n=45\\\bar x=25.5\\s=19.1\\\alpha =0.05[/tex]

(a)

The hypothesis for the test can be defined as follows:

H₀: The mean commute time in the U.S. is not less than half an hour, i.e. μ ≥ 30.

Hₐ: The mean commute time in the U.S. is less than half an hour, i.e. μ < 30.

(b)

As the population standard deviation is not known we will use a t-test for single mean.

Compute the test statistic value as follows:

 [tex]t=\frac{\bar x-\mu}{s/\sqrt{n}}=\frac{25.2-30}{19.1/\sqrt{45}}=-1.58[/tex]

Thus, the test statistic value is -1.58.

(c)

Compute the p-value of the test as follows:

[tex]p-value=P(t_{(n-1)}<-1.58)=P(t_{(45-1)}<-1.58)=0.061[/tex]  

*Use a t-table.

The p-value of the test is 0.061.

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 = 0.061> α = 0.05

The null hypothesis will not be rejected at 5% level of significance.

Thus, concluding that the mean commute time in the U.S. is less than half an hour.