1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Readme [11.4K]
2 years ago
9

The Environmental Protection Agency (EPA) publishes fuel economy values that are known to be good estimates of the fuel economy

a typical driver will achieve under average driving conditions. One of the fuel economy values the EPA publishes is a combined estimate, which represents a combination of city driving (55%) and highway driving (45%). A large car rental company has 16 Ford Explorers in their fleet. They collected fuel economy data from these cars and calculated the sample mean to be 23.29 mpg and sample standard deviation as 0.78 mpg.
Required:
The car rental company is willing to assume that the conditions are met for constructing a confidence interval. Use the collected data to construct a 90% confidence interval for the mean combined fuel economy for Ford Explorers.
Mathematics
1 answer:
r-ruslan [8.4K]2 years ago
7 0

Answer:

The 90% confidence interval for the mean combined fuel economy for Ford Explorers is between 22.95 and 23.63 mpg.

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 = 16 - 1 = 15

90% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 15 degrees of freedom(y-axis) and a confidence level of 1 - \frac{1 - 0.9}{2} = 0.95. So we have T = 1.7531

The margin of error is:

M = T\frac{s}{\sqrt{n}} = 1.7531\frac{0.78}{\sqrt{16}} = 0.34

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 23.29 - 0.34 = 22.95 mpg

The upper end of the interval is the sample mean added to M. So it is 23.29 + 0.34 = 23.63 mpg

The 90% confidence interval for the mean combined fuel economy for Ford Explorers is between 22.95 and 23.63 mpg.

You might be interested in
Find the largest interval which includes x = 0 for which the given initial-value problem has a unique solution. (Enter your answ
Ivan

Answer:

(-\infty,3)

Step-by-step explanation:

We are given that

(x-3)y''+4y=x

y''+\frac{4}{x-3}y=\frac{x}{x-3}

y(0)=0

y'(0)=1

By comparing with

y''+p(x)y'+q(x)y=g(x)

We get

p(x)=\frac{4}{x-3}

g(x)=\frac{x}{x-3}

q(x)=0

p(x),q(x) and g(x) are continuous for all real values of x except 3.

Interval on which p(x),q(x) and g(x) are continuous

(-\infty,3)and (3,\infty)

By unique existence theorem

Largest interval which contains 0=(-\infty,3)

Hence, the larges interval on which includes x=0 for which given initial value problem has unique solution=(-\infty,3)

7 0
3 years ago
Help!giving brainliest and 30 points
eduard

Answer:

D 80

Step-by-step explanation:

step by step

350 +(-350)=0 + 5h = 750 + (-350) =400

5h/5 =400/5=80

h=80

7 0
3 years ago
Consider the reduction of the complex figure with a scale factor of 1
Aleksandr [31]

Answer:

25

Step-by-step explanation:

4 0
2 years ago
Read 2 more answers
The percent equivalent of 1.07 is ______ and the fraction equivalent is ______
lawyer [7]
1.07 as a percent is 107% 1.07 as a fraction is 1 1/14

Hope this helps!
6 0
3 years ago
Read 2 more answers
(a + b - c )(a + b + c )
True [87]

If you are looking for the expanded version, this is it. It is also possible to group either an a from (a^2 + 2b) or a b from (2ab + b^2). Hope this helps!

6 0
3 years ago
Read 2 more answers
Other questions:
  • Container A has radius ​r​ and height h . It holds a maximum of 44 ounces of water. Container B has radius 2.5r and height 4h .
    14·2 answers
  • -2(x + 4) + 6 = -3 solve for x
    13·1 answer
  • Which graph represents the solution set of this inequality? 9−4d≥−3
    9·2 answers
  • Tyrell is constructing an angle congruent to angle Q. The work he has done so far is shown below.
    8·1 answer
  • How do you subtract: a negative number minus a positive number?
    8·1 answer
  • What is 4,124.307 rounded to the nearest hundredth?
    12·2 answers
  • Which of these are qualdrilateral
    15·2 answers
  • Stanley practices his running, swimming and biking every day. During these practices he runs at 9 mph, bikes at 16 mph and swims
    11·2 answers
  • What is the range of the data set? {43.2, 46.8, 44.5, 46.8, 44.2, 41.9, 45.8, 46.9, 41.2, 46.8, 44.1}
    14·1 answer
  • Given:f(x)=3x^2+1,G(x)=2x-3,H(x)=x<br> F(-2)=<br> a.13<br> b.37<br> c.-11
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!