A city councilwoman is concerned that the new contractor she hired is taking too long to replace defective streetlights. She would like to perform a hypothesis test to determine if the replacement time for streetlights under the new contractor is in fact longer than the replacement time under the previous contractor, which was 3.2 days on average. She selects a random sample of 12 streetlight service calls and obtains the following times to replacement (in days). Use a significance level of 0.05

6.2 7.15.4 5.57.52.6 4.3 2.9 3.7 0.7 5.6 1.7

Required:
a. Define μ in the context of the problem and state the appropriate hypotheses.
b. State and check the conditions for a hypothesis test of the mean. Since the sample size is smaller than 30, you will need to calculate a normal probability plot to determine if the data come from a normal distribution.

Answers

Answer 1

Answer:

There is significant evidence to conclude that the replacement time for streetlights under the new contractor is longer than the replacement time under the previous contractor.

Step-by-step explanation:

Given the data :

6.2 7.1 5.4 5.5 7.5 2.6 4.3 2.9 3.7 0.7 5.6 1.7

The hypothesis:

H0: μ = 3.2

H1 : μ > 3.2

n = sample size = 12

The sample mean, xbar = ΣX / n

xbar = 53.2 / 12

xbar = 4.43

Using calculator;

Sample standard deviation, s = 2.147

The test statistic :

(xbar - μ) ÷ (s/sqrt(n))

(4.43 - 3.2) ÷ (2.147/sqrt(12)

1.23 / 0.6197855

Test statistic = 1.985

The Pvalue using the Pvalue from Tscore calculator :

Tscore = 1.985 ; df = 12 - 1 = 11

Pvalue = 0.036

Since Pvalue < α ; We reject the Null

Hence, we conclude that the replacement time for streetlights under the new contractor is longer than the replacement time under the previous contractor.


Related Questions

pls help me on this !!!

Answers

Answer:

7, 12, 13

Step-by-step explanation:

Use the Pythagorean theorem equation on all of them. The one that does not make the equation true is the  answer.

a^2 + b^2 = c^2

A.

a^2 + b^2 = 18^2 + 80^2 = 6724

c^2 = 82^2 = 6724

Right triangle.

B.

a^2 + b^2 = 7^2 + 12^2 = 193

c^2 = 13^2 = 169

Not a right triangle.

C.

a^2 + b^2 = 3^2 + 4^2 = 25

c^2 = 5^2 = 25

Right triangle.

D.

a^2 + b^2 = 45^2 + 60^2 = 5625

c^2 = 75^2 = 5625

Right triangle.

Answer: 7, 12, 13

How to simplify this expression?

(12^15+12^30-12^49)/(-12^28+12^47-(144^6)/12)

Express the answer as 12^?.

Hint: You have to factor 12^? from the top or bottom so that the expression becomes x/(12^?)(x) or (12^?)(x)/x. Then the x should cancel out, and you get 12^? as the answer.

Thanks!!

Answers

Answer:

[tex]12^-^2[/tex]

Step-by-step explanation:

I hope this helps.


PLEASE HELP !! ILL GIVE BRAINLIEST !!

Answers

Answer:

<DEC and <IHJ

Step-by-step explanation:

Alternate exterior angles are angles on the other side of a transveral and on the exterior area.

same thing as last. nearest 100th

Answers

Answer:

452.39 mi^2

Step-by-step explanation:

A = πr^2

A = π (12mi)^2

A = 452.39 mi^2

Please mark Brainliest :D

Please mark Brainliest :D

Mr. Newman owns a sporting good store. He got a shipment of 49 baseball bats. 21 of them were wooden bats, and the rest were aluminum. What fraction of the bats were wooden?
Fill in the answer in simplest form.

Answers

Answer:

3/7

Step-by-step explanation:

Help please due in 45 minutes!!

Answers

Answer:

x=4, y=5

Step-by-step explanation:

Download photo math and take a picture of it

A television screen is 7 inches tall and 10 inches wide. What is its area?

Answers

Answer:

70 inches^2

Step-by-step explanation:

7x10=70

15 PTS!!! HELP IMMEATLEY
Aaron is designing a party game in which he needs exactly 24 possible outcomes. Which sets of actions can he use to have a statistically fair game?

Randomly select an odd digit {1, 3, 5, 7, 9}, then flip a coin twice.

Randomly select a number from 1 to 16, then roll an 8-sided number cube with the digits 1 to 8.

Spin this and roll an 8-sided number cube with the digits 1 to 8.
Select a card from a set of cards with the letters A through N, then spin this once.
Select a card from a set of cards with the letters A through D, then spin this once.
Toss a coin twice, then roll a 6-sided number cube with the digits 1 to 6.

Answers

Answer:

Select a card from a set of cards with the letters A through D, then spin this once.

Spin this and roll an 8-sided number cube with the digits 1 to 8.

I’m stuck on this question??????????????

Answers

Answer:

You are? so am I

Step-by-step explanation:

Answer:

1. 49, 2. 245

Step-by-step explanation:

Add 16 and 33 together to get 49 minutes. That is what Blaire listens to in one day. Multiply that by 5 and you find out what she listens to in 5 days

NEED ANSWER ASAP WILL GIVE BRAINLIEST FOR CORRECT ANSWER

Answers

Answer:

y = 470 - 50x

Step-by-step explanation:

Total distance minus the distance covered in n number of hours if the speed is 50 mph.

What type of sequence is this? *
9, 14, 19, 24, 29, ..

Answers

Answer:

an arithmetic sequence

Step-by-step explanation:

I think it's because it adds 5 each time and in arithmetic sequences there's a common difference, so it'd be an arithmetic sequence :)

Plz help well mark brainliest if you are correct!

Answers

Answer:

12 centimenters.

Step-by-step explanation:

Answer:

6 cm

Step-by-step explanation:

We need to find the distance from R to s which is basically the radius, we know radius is r=d/2 to 12/2 (since 12 is diameter) is 6.

A ceramic vase was originally priced at $100 but went on sale for 50% off. If Ernesto bought the ceramic vase and paid 12% sales tax, how much did he pay in total?

Answers

Answer: he payed $56 in total

Explanation:
50% of 100 is 50.
50 time 1.12 is 56

Ernesto bought the ceramic vase for $56 including 12% tax.

What is the percentage?

A percentage is a value per hundredth. Percentages can be converted into decimals and fractions by dividing the percentage value by a hundred.

Given, A ceramic vase was originally priced at $100 but went on sale for 50% off.

∴ The discounted price is (50/100)×100 = $50.

Now after Ernesto bought the ceramic vase he had to pay a tax of 12%.

∴ {(100 + 12)/100}×50.

= (112/100)×50.

= 56.

So he paid $56 including 12% tax.

Learn more about percentages here :

https://brainly.com/question/24159063

#SPJ2

PLEASE HELP IMMEDIATELY!!

Answers

Answer:

}

Step-by-step e.xplanati:kljkjk

The given graph represents the function f(x) = 2(5)^x
[tex]f(x) = 2( {5})^{x} [/tex]
How will the appearance of the graph change if the a value in the function is decreased, but remains greater than 0​
a) the graph will increase at a slower rate
b) the graph will show a decreasing, rather than increasing, function
c) the graph will show an initial value that is lower on the y-axis
d) the graph will increase at a constant additive rate, rather than a multiplicative rate

Answers

Answer:

C

Step-by-step explanation:

in exponential equations f(x)=ab^x , a is the intial amount while b is the growth factor. you are just decreasing a so the intial value is lower (=^w^=)

Answer:

Step-by-step explanation:C

How many pairs of opposite sides are parallel? no pairs 1 pair 2 pairs​

Answers

Answer:

1 pair

Step-by-step explanation:

The top and bottom sides can go forever without crossing

Answer:

1

Step-by-step explanation: because the top and bottom a pair

Obtain the general solution:

(x-y)(4x+y)dx + x(5x-y)dy = 0

Answers

Answer:

y=2x

y=-x

d=0

Step-by-step explanation:

sorry iam not sure i just tray to help

Can a triangle be made using the side lengths of 5, 10, 2?

a
Yes
b
No, the sum of the shortest sides measures less than the longest side.
c
No, the sum of the shortest sides measures more than the longest side.

Answers

Answer:

The answer is C. No, the sum of...

help ples me i hate ixl

Answers

Answer:

200

Step-by-step explanation:

Base of the prism is a square

So

[tex]\\ \tt {:}\longrightarrow Area\:of\:base=(side)^2[/tex]

[tex]\\ \tt {:}\longrightarrow (5)^2[/tex]

[tex]\\ \tt {:}\longrightarrow 25cm^2[/tex]

Now

[tex]\\ \tt {:}\longrightarrow Volume=Area\:of\:Base\times Height[/tex]

[tex]\\ \tt {:}\longrightarrow 25\times 8[/tex]

[tex]\\ \tt {:}\longrightarrow 200cm^3[/tex]

PLEASE HELP
BRAINLIEST
NO FILE HOSTING LINKS!!
Answer each part. If necessary, round your answers to the nearest hundredth.

Answers

Answer:

a) 11/7 pages or about 1.57

b) 23/11 dollars or 2.09090909....... (goes on forever)

BRAINLIEST PLS

the price per gallon of gas with a $7 car wash is $3.19 and the price without the car wash is $3.39. When is it worth it to buy the car wash? When is it worth it if the car wash costs $2?

Answers

Answer:

The price per gallon of gas with a $7 car wash is $3.19

Then if you purchase x gallons of gas and also pay for the car wash, the total cost is:

C(x) = $7 + $3.19*x

In the case that you do not pay for the car wash, the cost per gallon is $3.39

Then the cost for x gallons of gas in this case is:

K(x) = $3.39*x

When is it worth it to buy the car wash?

We need to sett the equations:

C(x) = K(x)

This means that you pay exactly the same in both cases, but in one ( C(x)) you get the car wash and in the other not.

Then we need to solve:

$7 + $3.19*x = $3.39*x

$7 = ($3.39 - $3.19)*x = $0.20*x

$7/$0.20 = x = 35

Then for 35 gallons, is worth to buy the car wash.

In the case where the car wash costs $2, then the equation C(x) becomes:

C(x) = $2 + $3.19*x

Then if we solve the same equation:

C(x)  =K(x)

$2 + $3.19*x = $3.39*x

$2 = ($3.39 - $3.19)*x

$2 = $0.20*x

$2/$0.20 = x

10 = x

Then for 10 galons is whort  buy the car wash.

Please help me thanks!

Answers

Answer:

3rd Option

[tex] \frac{6}{17} [/tex]

Step-by-step explanation:

Given,

No. of blue marbles = 6

No. of green marbles = 6

No. of red marbles = 5

So,

Total no. of marbles = 6+6+5 = 17

Therefore,

Probability of not getting blue marbles

[tex] = \frac{6}{17} [/tex]

Hence,

3rd option is correct.

LOOK AT IMAGE PLEASE I MARK BRAINLIEST

Answers

Answer:

0.2 I think

Step-by-step explanation:

7x6=42

35÷42=0.2

Answer: 5

explanation:
Area: base x height

35/7=5

Find the lateral area of a cylinder
whose radius is 5 cm and whose
height is 10 cm.
Round to the nearest whole number.
[? ] cm2

Answers

Answer:

314 cm^2

Step-by-step explanation:

(=^w^=)

A= 2*pi*r*h

A=2*pi*5*10

A=314.16 cm^2

Step-by-step explanation:

2×5×10=

10×10= 100 cm²

=100 cm²

An expression is shown below:

2x3y + 8xy − 4x2y − 16y

Part A: Rewrite the expression by factoring out the greatest common factor. (4 points)

Part B: Factor the entire expression completely. Show the steps of your work. (6 points)

Plz help, give good answer and get brainlest!!

Answers

Answer:

Part A: Rewrite the expression by factoring out the greatest common factor. (4 points)

answer:

2y(x³+4x-2x²-8)

Part B: Factor the entire expression completely. Show the steps of your work. (6 points)

answer:

2y(x³+4x-2x²-8)

2y(x³-2x²+4x-8)

2y(x²(x-2)+4(x-2))

2y(x²+4)(x-2)

Country A has an exponential growth rate of 4.6​% per year. The population is currently 5,849​,000, and the land area of Country A is 38​,000,000,000 square yards. Assuming this growth rate continues and is​ exponential, after how long will there be one person for every square yard of​ land?

Answers

There will be one person per square yard when the number of people is equal to the number of square yards of the country.
In other words, we need to know when the population of the country will be 27,000,000,000.
We know that the population grows exponentially, so we use the exponential growth formula:

Where:
P is the population as a function of time
is the initial population
r is the annual growth rate
t is time in year.
The information we have allows us to conclude that:


So the exponential growth equation is:

We want to know when P = 27, 000,000,000.
So:

Now we solve for t, and as soon as we answer for t, the answer will be 189.66 years. Hope this helps! Mark brainly please!


Answer:

195.205998 years

Step-by-step explanation:

P=P0(1.046)^t   P=future population   P0=initial population  t=years passed

38,000,000,000 = 5,849,000(1.046)^t

1.046^t = 38,000,000,000/5,849,000

1.046^t = 38,000,000/5,849

plug in log on both sides

log 1.046^t = log (38,000,000/5,849)

t[log 1.046] = log (38,000,000/5,849)

t = In (38,000,000/5,849)/ In 1.046

t ≈ 195.205998 (hope this helps)

Y = 5x + 2
6y = 18x + 12
What is the value of X?

Answers

Step-by-step explanation:

x= 0, y = 2

have a great day


PLEASE HELP !! ILL GIVE BRAINLIEST !!

Answers

Answer:

Step-by-step explanation:

Equation: (3x+7) + (10x+17) = 180

*These are consecutive interior angles and they add to 180 degrees

1.) Add like terms

13x + 24 = 180

2.) Subtract 24 from both sides

13x = 156

3.) Divide each side by 13

x = 12

*Substitute x in both expressions to get angle measures

Value of x: 12

3(12)+7 = 36+7 = 43

10(12)+17 = 120+17 = 137

*Check 43+137 = 180

Angle Measures: 1st angle: 43 degrees

2nd angle = 137 degrees

I already know the answer but ima check and see.

Answers

I got 2.29 is the difference and debras cows made more obviously

Fraction form is 229/100


MARK ME BRAINLIEST PLEASE

what is the domain of this exponential function , y=7^x

Answers

Answer: hope this helps

Step-by-step explanation:

Answer:

Hope this helped!!!

Step-by-step explanation:

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