Some transportation experts claim that it is the variability of speeds, rather than the level of speeds, that is a critical factor in determining the likelihood of an accident occurring (Update, Virginia Department of Transportation, Winter 2000). One of the experts claims that driving conditions are dangerous if the variance of speeds exceeds 75 (mph)2. On a heavily traveled highway, a random sample of 55 cars revealed a mean and a variance of speeds of 62.5 mph and 94.7(mph)2, respectively. (You may find it useful to reference the appropriate table: chi-square table or F table)
1. Set up the competing hypothesis to test wxpert,s claim.
2. At the 5% significance level find the critical value and state the decision rule.
3. Can you conclude that driving conditions are dangerous on this highway? explain.

Answers

Answer 1

Answer:

Explained below.

Step-by-step explanation:

The claim made by an expert is that driving conditions are dangerous if the variance of speeds exceeds 75 (mph)².

(1)

The hypothesis for both the test can be defined as:

H₀: The variance of speeds does not exceeds 75 (mph)², i.e. σ² ≤ 75.

Hₐ: The variance of speeds exceeds 75 (mph)², i.e. σ² > 75.

(2)

A Chi-square test will be used to perform the test.

The significance level of the test is, α = 0.05.

The degrees of freedom of the test is,

df = n - 1 = 55 - 1 = 54

Compute the critical value as follows:

[tex]\chi^{2}_{\alpha, (n-1)}=\chi^{2}_{0.05, 54}=72.153[/tex]

Decision rule:

If the test statistic value is more than the critical value then the null hypothesis will be rejected and vice-versa.

(3)

Compute the test statistic as follows:

[tex]\chi^{2}=\frac{(n-1)\times s^{2}}{\sigma^{2}}[/tex]

    [tex]=\frac{(55-1)\times 94.7}{75}\\\\=68.184[/tex]

The test statistic value is, 68.184.

Decision:

[tex]cal.\chi^{2}=68.184<\chi^{2}_{0.05,54}=72.153[/tex]

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

Conclusion:

The variance of speeds does not exceeds 75 (mph)². Thus, concluding that driving conditions are not dangerous on this highway.


Related Questions

-1 1/3 divided (-1.6)

Answers

Answer:

0.8333125

Step-by-step explanation:

Answer:

0.83

Step-by-step explanation:

One side of a triangle is half the longest side. The third side is 10 meters less than the longest side. The perimeter is 45 meters. Find all three sides.
m (smallest value)
m
m (largest value)

Answers

2x+x+2x-10 = 45

2x+x+2x-10 = 55

5x = 55

X=11

Smallest - 11 m
Largest - 22 m
3rd side - 12 m

A number is equal to the difference of four times the number and 18

Answers

Answer:

X = 4x-18

Step-by-step explanation:

X = “a number”^^

Will mark brainliest

Answers

Answer: The third option

y = -6 + 2√6 ÷ 5    and   y = -6 - 2√6 ÷ 5

Plz mark brainliest:)

The answer should be 3

What is 5 to the second power

Answers

it is basically asking what is 5 squared which is 25!!

Answer:

25

Step-by-step explanation:

5 times 5

5x5=25

hope this helps

a maple tree shades an area of 7 1/2 m square. in the scale drawing, the maple tree shades an area of 12 1/2 cm square. in the scale drawing how many square centimeters represents 1 m squared

Answers

The number of centimeter squares in the scale drawing for each 1 m squared is 1.67.

What is Scale factor?

The scale factor is a type of measurement which is used to increase or decrease the size of an object keeping its shape as the same. It can be determined by taking the ratio of the new and the original dimension of the object.

Given that,

The area shaded by a maple tree is 7(¹/₂) m².

And, the area shaded in scale drawing is 12(¹/₂) cm².

The required  number of square centimeters can be found by dividing the two areas as follows,

12(¹/₂) / 7(¹/₂)

= (25/2)/(15/2)

= 25 / 15

= 5 / 3

= 1.67

Hence, the number of centimeter squares in the scale area is 1.67.

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What is 1 hundredth ÷ 10?
1 hundredth ÷ 10 =

Answers

Answer:

.001 or 1 thousandth

Step-by-step explanation:

.01/10=.001

how do you find the solution to this inequality? please explain to me step by step how to do this
x - 8 > -3​

Answers

Answer:

x > 5

Interval form: (5, infinity)

Step-by-step explanation:

Just add 8 to both sides of the inequality:

x > 5

Therefore, x must be greater than 5.

Which are removable discontinuities?
x = -2
x = -2 and x = 0
x = 0 and x = 4
x = -2, x = 0, and x = 4

Answers

Answer:

C

Step-by-step explanation:

Got it right on eng

Answer:C

Step-by-step explanation:

g The average lifespan for a certain type of vehicle is 8 years and follows an exponential distribution. A lot contains 200 of these vehicles, brand new. What is the probability that 50 or more of them fail in the first 2 years

Answers

Answer:

The probability is [tex]P(A \ge 50 ) = 0.14321[/tex]

Step-by-step explanation:

The average life span is  [tex]\pi = 8[/tex]

The sample size is n =  200

Generally we are told that average lifespan for a certain type of vehicle follows an exponential distribution

i.e  

             [tex]X \~ \ \ \ exp(8)[/tex]

Gnerally the probability distribution function for exponential distribution is

       [tex]f(x) = \left \{ {{\lambda * e^{-\lambda * x }\ \ \ x\ge 0 } \atop {0 \ \ \ \ \ \ \ \ \ \ x < 0}} \right.[/tex]

Now [tex]\lambda[/tex] is the  constant which is evaluated as

      [tex]\lambda = \frac{1}{\pi}[/tex]

=>   [tex]\lambda = \frac{1}{8}[/tex]

=>   [tex]\lambda = 0.125[/tex]

Generally the that the vehicles will fail in less than 2 years is  mathematically represented as

         [tex]P(X \le 2 )= p= \int\limits^2_0 {\lambda e^{- \lambda * x} } \, dx[/tex]

        [tex]P(X \le 2 )= p= [ {0.125 * - \frac{1}{0.125 } e^{- 0.125 * x} } ]|\left 2 } \atop {0}} \right.[/tex]

       [tex]P(X \le 2 )= p= [ {0.125 * - \frac{1}{0.125 } e^{- 0.125 * 2} } ] - [ {0.125 * - \frac{1}{0.125 } e^{- 0.125 * 0} } ][/tex]

     [tex]P(X \le 2 )= p= -0.77880 + 1[/tex]

     [tex]P(X \le 2 )= p= 0.2212[/tex]

Generally the probability that the vehicle will fail in the first 2 years follows a binomial  distribution  with the mean evaluated as

         [tex]\mu = n * p[/tex]

=>      [tex]\mu = 200 * 0.2212[/tex]

=>      [tex]\mu = 44.24[/tex]

The standard deviation is

       [tex]\sigma = \sqrt{np(1 - p)}[/tex]    

      [tex]\sigma = \sqrt{200 * 0.2212 (1 - 0.2212)}[/tex]  

      [tex]\sigma = 5.86[/tex]

Using normal approximation of binomial  distribution the  probability that 50 or more of them fail in the first 2 years is mathematically represented as

   [tex]P(A \ge 50 ) = 1 - P(A < 50 )[/tex]

Applying continuity correction

    [tex]P(A \ge 50.5 ) = 1 - P(A < 50.5 )[/tex]

Here

    [tex]P(A < 50.5 ) = P(\frac{A - \mu }{\sigma} < \frac{50 - 44.24}{5.87} )[/tex]

Generally  

       [tex]\frac{A - \mu }{\sigma} = Z (The \ standardized \ value \ of A )[/tex]

=> [tex]P(A < 50.5 ) = P( Z < 1.0664 )[/tex]

From the z-table the probability value  of  ( Z  <  1.0664   ) is  

     [tex]P( Z < 1.0664 ) = 0.85679[/tex]

So  

   [tex]P(A \ge 50 ) = 1 - 0.85679[/tex]

=> [tex]P(A \ge 50 ) = 0.14321[/tex]

HELP ME get the altitude!!!!!

Answers

Add them all together

Graph each function and determine the y-intercept, then use the graph to determine the approximate value of the given expression.
Y=3^x;3^1.2
A. 1;3.7
B. 1;2.9
C. 0;3.9
D. 0;3.5

Answers

Answer: Its A) 1 ; 3.7

Step-by-step explanation:i just took the practice on edge 2020

Suppose that your boss must choose four employees in your office to attend a conference in Jamaica. Because all 12 of you want to go, he decides that the only fair way is to draw names out of a hat. What is the probability that you, Charles, Margaret, and Sean are chosen?

Answers

Using the combination formula, it is found that the probability that you, Charles, Margaret, and Sean are chosen is:

[tex]p = \frac{1}{495}[/tex].

What is the combination formula?

[tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by:

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

In this problem, 4 people will be chosen from a set of 12, hence the number of ways to choose them is:

[tex]C_{12,4} = \frac{12!}{4!8!} = 495[/tex]

The desired combination is only one, hence the probability is:

[tex]p = \frac{1}{495}[/tex].

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what is 100,789,388,369,012 times 479,000,000

Answers

Answer:

4.8278117e+22

Step-by-step explanation:

48278117028756748000000
Pls mark brainliest

Using the Smith's BBQ Report, liquor sales for both weeks account for approximately what percentage of beverage sales for both weeks?
A 50%
B 40%
C 30%
D 20%

Answers

It’s a because of the beverage percentages

Answer:d

Step-by-step explanation:

what is the equation of the line for figures G and
H

Answers

Answer:

B = C + (C - A) = (51/50 + 51/50 - 2, 457/50 + 457/50 - 9) = (1/25, 232/25).

Step-by-step explanation:

Is the function even, odd, or neither?

Answers

Answer:

The function is neither even or odd

Step-by-step explanation:

Felipe has a flower bed

Answers

Answer:

man thats cool

Step-by-step explanation:

LoL guess Pelipe is happy

peter ​says, "If you subtract 11 from my number and multiply the difference by -2​, the result is -26." What is Peter's number?

Answers

Answer:

24

Step-by-step explanation:

Reverse

-26/-2= 13

13+11=24

Check

24-11=13

13×-2= -26

I beleive the answer is 7.5 because -26 plus 11 = -15 then -15 divided by -2 = 7.5

this is probably wrong I didnt do it on paper

There are 454 grams in a pound. Convert 330 grams to ounces.

Answers

U have to Substract the numbers and then there your answer

11.6 ounces

330g x 1lb/454g x 16oz/1lb = 11.6 ounces

If the conversion factors are properly set up and all numbers are correct, the unwanted units cancel out leaving the units of the final answer.  (citing my source usa test prep but i worked it out.)

What is the solution of a - 3 = -7

Answers

Answer:

-4

Step-by-step explanation:

take -3 to other side or        add 3 to both sides

So, a=-7+3

       =-4

if f(x) = 6(x - 2)3 + 5, what is the y- intercept?​

Answers

Answer:

y= (0, -31)

Step-by-step explanation:

Hope this helps

A food truck sells tacos $1.25 a piece. The truck operator earned $360.00 last night.
How many tacos did the food truck sell last night?
28.8 tacos
288 tacos
300 tacos
2.88 tacos

Answers

Answer:

288

Step-by-step explanation:

Each taco is 1.25 dollars and you are trying to figure out how many tacos he sold to do this we make an equation.

Step 1

1.25 x = 360

x =is the amount of tacos sold.

Step 2

1.25 x = 360

/1.25      /1.25

to get x on its own we need to cancel out the 1.25 so we dived because it was multiplied to the x. we did the same on the other side to balance the equation.

Step 3

x = 288

we now need to identify what x is, we can see it is 288. If we trade x for what it means it is then this is your answer  the amount of tacos sold=288

i hope this helps ;)

Suppose your cell phone plan charges a fixed rate of $10 per month plus 7 cents per minute. Create a table that shows the relationship between the total number of minutes you might use each month, m, and your total monthly cell phone bill, t.

Answers

Create a table =10t+7m

I need the right answers pls and tysmmm

Answers

Answer:

It's 21, you are correct!!

Step-by-step explanation:

4(x - 2 + y) =4(x−2+y)=4, left parenthesis, x, minus, 2, plus, y, right parenthesis, equals

ill put in 50 brainly points

Answers

Answer:

x=4 and y=2

Step-by-step explanation:

The correct equation is,

⇒ y = - x + 3

What is an expression?

Mathematical expression is defined as the collection of the numbers variables and functions by using operations like addition, subtraction, multiplication, and division.

We have to given that;

The expression is,

⇒ 4 (x - 2 + y) = 4

Now, Simplify the expression as;

⇒ 4 (x - 2 + y) = 4

⇒ x - 2 + y = 4/4

⇒ x - 2 + y = 1

⇒ x + y = 1 + 2

⇒ x + y = 3

⇒ y = - x + 3

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I can't solve this problem: 47 x 98= ( ? x 47)-(2 x 47)

Answers

Answer:

The answer to your question is:

2 and -49

Step-by-step explanation:

2 x -49 = -98

2 + (-49) = -47

x2 - 47x - 98 = 0

The solution to factor the quadratic equation above is:

(X + 2 ) (X - 49)

Since 2 and -49 multiply to -98 and add up -47, you know that the following is true:

x2 - 47x - 98 = (X + 2 ) (X - 49)

para calcular el tanto por ciento de una cantidad tengo que​

Answers

Answer:

Your answer is: Use the percentage formula: P% * X = Y  

Step-by-step explanation:

Hope this helped : )  

Su respuesta es: Utilice la fórmula de porcentaje: P% * X = Y

Espero que esto haya ayudado :)

134d) Graph the hyperbola, identify the center, vertices, foci, and equations of the asymptotes

49y^2−25x^2−196y−200x−1429=0

IF YOU ARE GOOD AT MATH, PLEASE HEAD OVER TO MY PROFILE, IN THE QUESTIONS TAB AND ANSWER THE QUESTIONS STARTING FROM THE ONE MARKED 132B!

best answers get marked 'brainliest'!

Thank you!

Answers

Answer:

Step-by-step explanation:

49y^2 - 25x^2 - 196y - 200x = 1429

49y^2-196y+196 - 25x^2-200x-400 = 1429+196-400

49(y-2)^2 - 25(x+4)^2 = 1225

(y-2)^2/25 - (x-4)^2/49 = 1

So now you know that you have an hyperbola with

center at (-4,2)

foci at (-4,2±[tex]\sqrt{74}[/tex])

vertices at (-4,2±5)

asymptotes 7y±20 = ∓5x+14

Calculate 3cm ,4cm, 10cm and 2cm

Answers

Answer:

19cm

Step-by-step explanation:

(chose one way)

1. way using commutativity

(3cm+4cm)+(10cm+2cm)=7cm+12cm=19cm

2. way just writing

3cm+4cm+10cm+2cm=19cm

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