Many freeways have service (or logo) signs that give information on attractions, camping, lodging, food, and gas services prior to off-ramps. These signs typically do not provide information on distances. An article reported that in one investigation, six sites along interstate highways where service signs are posted were selected. For each site, crash data was obtained for a three-year period before distance information was added to the service signs and for a one-year period afterward. The number of crashes per year before and after the sign changes were as follows.
Before 13 22 65 123 56 63
After 14 21 43 84 75 72
1. The article included the statement "A paired t-test was performed to determine whether there was any change in the mean number of crashes before and after the addition of distance information on the signs." Carry out such a test. (Note: The relevant normal probability plot shows a substantial linear pattern.)
a. State and test the appropriate hypotheses. (Use α = 0.05.)
b. Calculate the test statistic and P-value. (Round your test statistic to two decimal places and your P-value to three decimal places.)
t = _____
p-value = _____
c. State the conclusion in the problem context.
A. Fail to reject H0. The data does not suggest a significant mean difference in the average number of accidents after information was added to road signs.
B. Reject H0. The data suggests a significant mean difference in the average number of accidents after information was added to road signs.
C. Fail to reject H0. The data suggests a significant mean difference in the average number of accidents after information was added to road signs.
D. Reject H0. The data does not suggest a significant mean difference in the average number of accidents after information was added to road signs.
2. If a seventh site were to be randomly selected among locations bearing service signs, between what values would you predict the difference in the number of crashes to lie? (Use a 95% prediction interval. Round your answers to two decimal places.)

Answers

Answer 1

Answer:

Test statistic = 0.63

Pvalue = 0.555

A. Fail to reject H0. The data does not suggest a significant mean difference in the average number of accidents after information was added to road signs.

Step-by-step explanation:

Given :

Before 13 22 65 123 56 63

After_ 14 21 43 84 75 72

To perform a paired t test :

H0 : μd = 0

H1 : μd ≠ 0

We obtain the difference between the two dependent sample readings ;

Difference, d = -1, 1, 22, 39, -19, -9

The mean of difference, Xd = Σd/ n = 33/6 = 5.5

The standard deviation, Sd = 21.296 (calculator).

The test statistic :

T = Xd ÷ (Sd/√n) ; where n = 6

T = 5.5 ÷ (21.296/√6)

T = 5.5 ÷ 8.6940555

T = 0.6326

The Pvalue : Using a Pvalue calculator ;

df = n - 1 = 6 - 1 = 5

Pvalue(0.6326, 5) = 0.5548

Decision region :

Reject H0 ; If Pvalue < α; α = 0.05

Since 0.5548 > 0.05 ; we fail to reject the Null and conclude that the data does not suggest a significant mean difference in the average number of accidents after information was added to road signs.


Related Questions

Simplify: −4(b+6)−2b(1−4b

Answers

Step-by-step explanation:

-4b-24-2b+8b2

8b2-6b-24=0

Which of the following choices is equivalent to the equation below?

5(2x−1) = 5(5x−14)

A 2x − 1 = 5x − 14
B 5(2x − 1) = 5x − 14
C 2x − 1 = 5
D None of these choices are correct.

Answers

Answer:

2x-1 = 5x-14

Step-by-step explanation:

5(2x−1) = 5(5x−14)

Divide each side by 5

5/5(2x−1) = 5/5(5x−14)

2x-1 = 5x-14

Answer:

A.

Step-by-step explanation:

5(2x−1) = 5(5x−14)

10x - 5 = 25x - 70

65 = 15x

x = 13/3.

Take Option A.

2x - 1 = 5x - 14

3x = 13

x = 13/3 so its this one.

B: 10x - 5 = 5x - 14

5x = -9

x = -9/5 so NOT B.

C. simplifies to x = 3. so NOT C.

A consumer advocate agency is concerned about reported failures of two brands of MP3 players, which we will label Brand A and Brand B. In a random sample of 197 Brand A players, 33 units failed within 1 year of purchase. Of the 290 Brand B players, 25 units were reported to have failed within the first year following purchase. The agency is interested in the difference between the population proportions, , for the two brands. Using the data from the two brands, what would be the standard error of the estimated difference, Dp = A – B, if it were believed that the two population proportions were, in fact, equal (i.e., )?

Answers

Answer:

The standard error of the estimated difference is of 0.0313.

Step-by-step explanation:

To solve this question, we need to understand the central limit theorem, and subtraction of normal variables.

Central Limit Theorem

The Central Limit Theorem establishes 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.

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]

Subtraction between normal variables:

When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.

Brand A:

33 out of 197, so:

[tex]p_A = \frac{33}{197} = 0.1675[/tex]

[tex]s_A = \sqrt{\frac{0.1675*0.8325}{197}} = 0.0266[/tex]

Brand B:

25 out of 290, so:

[tex]p_B = \frac{25}{290} = 0.0862[/tex]

[tex]s_B = \sqrt{\frac{0.0862*0.9138}{290}} = 0.0165[/tex]

What would be the standard error of the estimated difference?

[tex]s = \sqrt{s_A^2+s_B^2} = \sqrt{0.0266^2+0.0165^2} = 0.0313[/tex]

The standard error of the estimated difference is of 0.0313.

Show why (2×3×7)^4 = 2^4 × 3^4 × 7^4 show work

Answers

I’m sorry really…. Need points
(2×3×7)⁴=2⁴×3⁴×7⁴the formula is a

[tex] {a}^{m} \times {b}^{m} = ( {ab)}^{m} [/tex]

(2×3×7)⁴=(2×3)⁴×7⁴(2×3×7)⁴=(2×3×7)⁴RHS=LHS

please mark this answer as brainlist

-36 = 6(2-8n) please

Answers

Answer:

n=1

Step-by-step explanation:

-36 = 6(2-8n)

-36=12-48n

-36-12=-48n

-48=-48n

n=1

HELP ME PLEASE I NEED HELP

Answers

Answer:

1. 3-5

2. 5-3

3. 3-5

4. 5-3

Step-by-step explanation:

This is simple! Just get rid of the parenthesis for each of the expressions shown.

3 + (-5)

the plus sign is next to the negative which is in the parenthesis. Negative times positive is equal to negative. The expression then becomes

3 - 5

Now do the same for the rest!

For things like 3 and 4, you can just flip it like 3-5 and 5-3 because it will all equal the same :]

Hope this helps !!

-Ketifa

What number increased by 30% is 34.5

Answers

Answer:

44.85

Step-by-step explanation:

There are two ways to do it, you can either multiply 0.3 by 34.5 and then add it to 34.5 to get 44.85, or you can add the 30% to 100% and get 1.3 which you multiply by 34.5 and that gets you 44.85

44.84 You’re welcome!

The following list shows the colours of a random selection of sweets.
red green red blue pink red
yellow pink blue yellow red yellow
Select the type of the data.CHOOSE ONE PLEASE HELP
Discrete

Continuous

Categorical

Quantitative

Answers

Answer:

Categorical or Continuous.

Step-by-step explanation:

Because the red appears in each colours (continuous)

Which graph best represents the equation –x + 2y = 4?

Answers

Answer:

C

Step-by-step explanation:

Convert the equation into slope intercept form : y=mx+b

2y=x+4

y=1/2x + 2

The m is the slope and the b is the y intercept

In this equation, the slope is 1/2 and the y intercept is 2

The only graph with y intercept 2 is C

What is the formula for the volume of a pyramid?

V = πr2h
V = 3/4πr2h
V = 1/3πr2h
V = 1/3Bh

Answers

Which behavior would best describe someone who has good communication skills with customers ? a) Following up with some customers b) Talking to customers more than listening to them c) Repeating back what the customer says d) Interrupting customers frequently
The formula is V=1/3Bh

write any five sentences of fraction?​

Answers

Step-by-step explanation:

Fractions represent equal parts of a whole or a collection. 

Fraction of a whole: When we divide a whole into equal parts, each part is a fraction of the whole. 

a fraction has 2 parts

The number on the top of the line is called the numerator. It tells how many equal parts of the whole or collection are taken.  The number below the line is called the denominator.  It shows the total divisible number of equal parts the whole into or the total number of equal parts which are there in a collection. 

There are different types of fraction

unit fractionimproper fractionproper fractionmixed fraction

What is distributive property???

Answers

A number multiplied by a sum is the same as the sum of the number multiplied by each addend; a(b + c) = ab + ac

Answer:

the distributive property of binary operations generalizes the distributive law from elementary algebra, which asserts that one has always For example, one has One says that multiplication distributes over addition.

Instructions: The polygons in each pair are similar. Find the
missing side length.

Answers

Answer:

missing side length is 12

Step-by-step explanation:

similar means that all correlating pairs of sides have the same ratio (old side length) / (new side length).

so, when we know the ratio of one pair, we can apply it to any other side to calculate the correlating side.

we see, when we go from small to large, that we have the ratio 32/40 = 4/5.

so, multiplying the larger side by this, we get the shorter side.

15 × 4/5 = 3 × 4 = 12

the proportion part in your picture is a bit confusing :

yes,

x/15 = 32/40 = 32/40

I don't know, why this last expression was repeated.

x/15 = 32/40

x = 15×32/40 = 15×4/5 = 3×4 = 12

as you see we get of course the same result doing it that way.

Calculate the break even sales dollars if the fixed expenses are $7,000 and the contribution ratio is 40%.

Answers

Answer:

Break even sales = $17,500 (Approx.)

Step-by-step explanation:

Given:

Fixed expenses = $7,000

Contribution ratio = 40%

Find:

Break even sales dollars

Computation:

Break even sales = Fixed expenses / Contribution ratio

Break even sales = 7,000 / 40%

Break even sales = 7,000 / 0.40

Break even sales = 17,500

Break even sales = $17,500 (Approx.)

Jason can peel 15 potatoes in 25 minutes. Janette can peel 8 potatoes in 1/10 hour. If they start peeling at the same time how many
minutes will it take them to peel 406 potatoes?

Answers

9514 1404 393

Answer:

  210 minutes

Step-by-step explanation:

Jason's rate of peeling is ...

  (15 potatoes)/(25 minutes) = 15/25 potatoes/minute = 3/5 potatoes/minute

Janette's rate of peeing potatoes is ...

  (8 potatoes)/(6 minutes) = 4/3 potatoes/minute

Their combined rate is ...

  (3/5 +4/3) = (9 +20)/15 = 29/15 . . . . potatotes/minute

Then the time required for 406 potatoes is ...

  (406 potatoes)/(29/15 potatoes/minute) = (406×15/29) minutes

  = 210 minutes

Find the length of the arc.
A. 21/π4 in
B. 18π in
C. 45/π8 in
D. 1890π in

Answers

Answer:

we know that all Lenght of circle is 2πr so 2*π*7=14π

Step-by-step explanation:

14π equal to 360°

but we need just 135° so we should write it kind of radian(π)

if 14π=360°

x=135°

14π*135=360°*x 14π*27=72*x ........= 14π*3=8*x

7π*3=4*x ....... X=21π/4

The length of the arc is 21/π4 in

An answer is an option A. 21/π4 in

What is the arc of the circle?

The arc period of a circle can be calculated with the radius and relevant perspective using the arc period method.

⇒angle= arc/radius

 ⇒  135°=arc/7

⇒ arc =135°*7

  ⇒arc=135°*π/180° *7in

⇒arc = 21/π4 in

Learn more about circle here:-brainly.com/question/24375372

#SPJ2

In the figure, find the measure of TU⎯⎯⎯⎯⎯⎯⎯⎯

Answers

Answer:

TU = 27

Step-by-step explanation:

We are given two secant segments that are drawn from a circle to meet at an exterior point of the circle. Thus, according to the secant secant theorem, the product of the measure of one secant segment and its external secant segment equals that of the product of the other and its external secant segment.

Thus:

VU*TU = VW*BW

Substitute

7(x + 4) = 9(-2 + x)

7x + 28 = -18 + 9x

Collect like terms

7x - 9x = -18 - 28

-2x = -46

Divide both sides by -2

x = -46/-2

x = 23

✔️TU = x + 4

Plug in the value of x

TU = 23 + 4

TU = 27

A simple random sample of 400 individuals provides 112 Yes responses. (a) What is the point estimate of the proportion of the population that would provide Yes responses

Answers

Answer:

The point estimate of the proportion of the population that would provide Yes responses is 0.28.

Step-by-step explanation:

Point estimate of the proportion of the population that would provide Yes

The sample proportion of yes responses.

In the sample:

112 yes responses in the sample of 400, so:

[tex]p = \frac{112}{400} = 0.28[/tex]

The point estimate of the proportion of the population that would provide Yes responses is 0.28.

Determine a scalar c so that the angle between a = i + cj and b = i + j is 45°.​

Answers

Answer:

c=0

Step-by-step explanation:

ATQ a.b=|a||b|sin(45)

1+c=sqrt(1+c^2)*sqrt(2)*1/sqrt(2)

1+c=sqrt(1+c^2)

(1+c)^2=(1+c^2)

2c=0, c=0

The required simplified value of c is zero for which the angle between a and b is 45°.

What is a vector?

Vector is defined as the quantities that have both magnitude and direction are called a vector quantity and the nature of the quantity is called a vector.  

Here,
scaler product is given as,
a . b = |a|.|b|cos45
(i + cj). (i + j) = √[1² + c²] . √[1²+1²] × 1/√2
1 + c = √1 + c²

Squaring both sides
(1 + c)² = 1 + c²
1 + c² + 2c =1 + c²
2c = 0
c = 0

Thus, the required simplified value of c is zero for which the angle between a and b is 45°.

Learn more about vectors here,

https://brainly.com/question/13322477
#SPJ2

56 x 10^-4)
Group of answer choices

2.37 x 10^-16

4.21 x 10^15

2.4 x 10^-16

4.2 x 10^15

Answers

9514 1404 393

Answer:

  (d)  4.2×10^15

Step-by-step explanation:

Your calculator will tell you the quotient is about ...

  4.21348...×10^15

The least precise number in the division is 1.5, which has 2 significant digits. Therefore, the result should be rounded to 2 significant digits:

  4.2×10^15

The whole number 23 is an example of a ____ number.

prime or composite?

Answers

The answer is prime! I hope this helps you out!

Answer:

23 is a prime number. Reason: Prime number are those numbers which are divisible by 1 and itself. Example: 5 is divisible by 1 and 5 only.

helpppp asap pleaseee

Answers

Answer:

29/3 is your answer

Step-by-step explanation:

pls mark as brainliest

Which of the following is a solution to 6x - 5y=4?
(2,7)
(-1, -2)
(-2, -1)
(2, -7)

Answers

Answer:

2,7

Step-by-step explanation:

Answer:

(-1,-2)

Step-by-step explanation:

(6 x -1) -(-2 x 5) = 4

-6 + 10 = 4

Use the discriminant to describe the roots of each equation. Then select the best description.
7x² + 1 = 5x

Answers

Answer:

Imaginary roots

Step-by-step explanation:

The discriminant of a quadratic in standard form [tex]ax^2+bx+c[/tex] is given by [tex]b^2-4ac[/tex].

Given [tex]7x^2+1=5x[/tex], subtract 5x from both sides so that the quadratic is in standard form:

[tex]7x^2-5x+1=0[/tex]

Now assign variables:

[tex]a\implies 7[/tex] [tex]b\implies -5[/tex] [tex]c\implies 1[/tex]

The discriminant is therefore [tex](-5)^2-4(7)(1)=25-28=\textbf{-3}[/tex].

What does this tell us about the roots?

Recall that the discriminant is what is under the radical in the quadratic formula. The quadratic formula is used to find the solutions of a quadratic. Therefore, the solutions of this quadratic would be equal to [tex]\frac{-b\pm \sqrt{-3}}{2a}[/tex] for some [tex]b[/tex] and [tex]a[/tex]. Since the number under the radical is negative, there are no real roots to the quadratic (whenever the discriminant is negative, the are zero real solutions to the quadratic). Therefore, the quadratic has imaginary roots.

Wayne has a rectangular painting. The width of the painting is
5/6

of a foot, and the length is
3/4
of a foot. What is the area of the painting?

Answers

Answer:

5/8 ft^2

Step-by-step explanation:

The area of a rectangle is given by

A = l*w  where l is the length and w is the width

A = 5/6 * 3/4

A = 3/6 * 5/4

A = 1/2 * 5/4

A = 5/8 ft^2

WHAT IS X³-27 SIMPLIFIED

Answers

Answer:

It is (x - 3)³ - 9x(3 - x)

Step-by-step explanation:

Express 27 in terms of cubes, 27 = 3³:

[tex] = {x}^{3} - {3}^{3} [/tex]

From trinomial expansion:

[tex] {(x - y)}^{3} = (x - y)(x - y)(x - y) \\ [/tex]

open first two brackets to get a quadratic equation:

[tex] {(x - y)}^{3} = ( {x}^{2} - 2xy + {y}^{2} )(x - y)[/tex]

expand further:

[tex] {(x - y)}^{3} = {x}^{3} - y {x}^{2} - 2y {x}^{2} + 2x {y}^{2} + x {y}^{2} - {y}^{3} \\ {(x - y)}^{3} = {x}^{3} - {y}^{3} + 3x {y}^{2} - 3y {x}^{2} \\ {(x - y)}^{3} = {x}^{3} - {y}^{3} + 3xy(y - x) \\ \\ { \boxed{( {x}^{3} - {y}^{3} ) = {(x - y)}^{3} - 3xy(y - x)}}[/tex]

take y to be 3, then substitute:

[tex]( {x}^{3} - 3^3) = {(x - 3)}^{3} - 9x(3 - x)[/tex]

The circle graph above shows the distribution of utility expenses for the Hierra family last year. If the family’s total utility expenses last year were $3,600, what were their expensive go water and sewer.
Water and sewer=X%
Electric=30%
Heating and gas=50%

Answers

Answer:

The correct answer is - $720 or 20%.

Step-by-step explanation:

Given:

Total expense = 3600

Electric=30%

Heating and gas=50%

Water and sewer=X%

Solution:

For electric: 3600*30/100 = 1080

for heating and gas: 3600*50/100 = 1800

Left money for expense of water and shower = total - (electric and heating)

= 3600-1880

= 720

Percentage of water and shower = 720*100/3600

= 20%

Answer:

Correct!

Step-by-step explanation:

Thank you this is correct :) I took the test

thank you for the help every one

Answers

Answer:

1. 1.66in

2. 6.66in

3. 3.33in

4. 1inch

Step-by-step explanation:

the area of a rectangle is found by multiplying the length times width or the two sides.

5 x 1/3 is about 1.66 inches

5 x 4/3 is about 6.66 inches

5/2 x 4/3 is about 3.33 inches

and 7/6 x 6/7 is 1 inch

What is the sum of the geometric sequence 1, 3, 9, ... if there are 10 terms? (5 points)

Answers

Answer:

[tex]S_n = \frac{1 (1 - 3^{10})}{1 - 3} = 29524[/tex]

Step-by-step explanation:

There's a handy formula we can use to find the sum of a geometric sequence, and here it is

[tex]S_n = \frac{a_1 (1 - r^n)}{1 - r}[/tex]

The value n represents the amount of terms you want to sum in the sequence. The variable r is known as the common ratio, and a is just some constant. Let's find those values.

First lets visualize this sequence

[tex]n_1 = 1\\n_2 = 1 + 3\\n_3 = 1 + 3 + 3^2\\n_4=1+3+3^2+3^3\\...[/tex]

Okay so there's clearly a pattern here, let's write it a bit more concisely. For each n, starting at 1, we raise 3 to the (n-1) power, add it to what we had for the previous term.

[tex]S_n = \sum{3^{n-1}} = 3^{1 - 1} + 3^{2 - 1} + 3^{3-1} ...[/tex]

Our coefficients of r, and a, are already here! As you can see below, r is just 3, and a is just 1.

[tex]S_n = \sum{a*r^{n-1}}[/tex]

To finish up lets plug these coefficients in and get our sum after 10 terms.

[tex]S_n = \frac{1 (1 - 3^{10})}{1 - 3} = 29524[/tex]

What is the discriminat of 2x+5x^=1

Answers

Answer:

don't know...........

It's 24 hope that's helps u out
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