Question

The Environmental Protection Agency (EPA) rates the mean highway gas mileage of the 2017 Chevrolet Sonic to be 28 miles per gallon. Assume the standard deviation is 3 miles per gallon. A rental company bought 60 of these cars.

a. What is the probability that the average mileage of the fleet is greater than 27.5 miles per gallon?

b. What is the probability that the average mileage of the fleet is between 27 and 27.8 miles per gallon?

c. What mileages would be considered unusual? (Recall unusual is the top and bottom 5%)

Answer #1

(A) using normalcdf

setting lower = 27.5

upper = 9999

mean = 28

standard deviation = 3/sqrt(60)

=normalcdf(lower, upper, mean, sd)

=normalcdf(27.5,9999,28,3/sqrt(60))

= 0.9016

(B)

using normalcdf

setting lower = 27

upper = 27.8

mean = 28

standard deviation = 3/sqrt(60)

=normalcdf(lower, upper, mean, sd)

=normalcdf(27,27.8,28,3/sqrt(60))

= 0.2979

(C) lower value = NORMINV(probability, mean, sd)

setting probability = 0.05

mean = 28 and sd = 3/sqrt(60)

=NORMINV(0.05,28,3/sqrt(60))

= 27.36

and

upper value = NORMINV(probability, mean, sd)

setting probability = 0.95

mean = 28 and sd = 3/sqrt(60)

=NORMINV(0.95,28,3/sqrt(60))

= 28.64

The Environmental Protection Agency rates the mean highway gas
mileage of the 2017 Chevrolet Sonic to be 28 miles per gallon.
Assume the standard deviation is 3 miles per gallon. A rental car
company buys 50 of these cars.
What is the probability that the mean gas mileage of the rental
fleet is less than 27.5 miles per gallon?
Find the 70th percentile of the mean mileage for the rental
fleet. Round your answer to two decimal digits.

The Environmental Protection Agency (EPA) fuel economy estimates
for automobile models tested recently predicted a mean of 24.8
miles per gallon, with a standard deviation of 6.2 miles per
gallon. Assume that a Normal model applies. Find the probability
that a randomly selected automobile will average:
1. Less than 20 miles per gallon.
2. More than 30 miles per gallon.
3. Between 25 and 32 miles per gallon

Fuel Efficiency of Manual and Automatic
Cars
Each year the US Environmental Protection Agency (EPA) releases
fuel economy data on cars manufactured in that year. Below are
summary statistics on fuel efficiency (in miles/gallon) from random
samples of cars with manual and automatic transmissions
manufactured in 2012. Do these data provide strong evidence of a
difference between the average fuel efficiency of cars with manual
and automatic transmissions in terms of their average city mileage?
Assume that conditions for inference...

We expect a car's highway gas mileage to be related to its city
gas mileage (in miles per gallon, mpg). Data for all 1137 vehicles
in the government's 2013 Fuel Economy Guide give the
regression line
highway mpg = 6.785 + (1.033 × city mpg)
for predicting highway mileage from city mileage.
(a) What is the slope of this line? (Enter your answer to three
decimal places.)
____mpg
Say in words what the numerical value of the slope tells us....

We expect a car's highway gas mileage to be related to its city
gas mileage (in miles per gallon, mpg). Data for all 1137 vehicles
in the government's Fuel Economy Guide give the regression
line
highway mpg = 6.785 + (1.033 * city mpg)
for predicting highway mileage from city mileage.
(a) What is the slope of this line? (Enter your answer to three
decimal places.)
mpg
Say in words what the numerical value of the slope tells us.
Highway...

The Environmental Protection Agency (EPA) fuel economy estimates
for automobile models tested recently predicted a mean of 24.8 mpg
and a standard deviation of 6.2 mpg for highway driving. Assume
that a Normal model can be applied.
a) Draw the model for auto fuel economy. Clearly label it,
showing what the 68-95-97 Rule predicts. Use StatCrunch, Excel, or
Minitab.
b) In what interval would you expect the central 68% of autos to
be found?
c) About what percent of autos...

The Environmental Protection Agency
measures a mean gas mileage for recently tested cars as 24.8 mpg
with a standard
deviation of 6.2 mpg. The dataset
on Fuel economy in StatCrunch gives an average of
24.2 mpg with a standard deviation of 6.5 mpg. Joe’s car is
estimated at 30 mpg.
(a) Calculate the z-scores to find the relative tab at both
sources (the Exercise and
the Dataset).
(b) Relative to the other cars,
with which source will Joe have
the...

In its Fuel Economy Guide for 2014 model vehicles, the
Environmental Protection Agency gives data on 1160 vehicles. There
are a number of high outliers, mainly hybrid gas-electric vehicles.
If we ignore the vehicles identified as outliers, however, the
combined city and highway gas mileage of the other 1134 vehicles is
approximately Normal with mean 22.8 miles per gallon (mpg) and
standard deviation 5.3 mpg.
The quintiles of any distribution are the values with cumulative
proportions 0.20, 0.40, 0.60, and...

A certain car model has a mean gas mileage of 31 miles per
gallon (mpg) with a standard deviation 3 mpg. A pizza delivery
company buys 43 of these cars. What is the probability that the
average mileage of the fleet is greater than 30.7 mph

In its Fuel Economy Guide for 2016 model vehicles, the
Environmental Protection Agency gives data on 1170 vehicles. There
are a number of high outliers, mainly hybrid gas-electric vehicles.
If we ignore the vehicles identified as outliers, however, the
combined city and highway gas mileage of the other 1146 vehicles is
approximately Normal with mean 23.0 miles per gallon and standard
deviation 4.9 mpg.
The quintiles of any distribution are the values with cumulative
proportions 0.20, 0.40, 0.60, and 0.80....

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 9 minutes ago

asked 12 minutes ago

asked 16 minutes ago

asked 16 minutes ago

asked 16 minutes ago

asked 38 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago