Problem 22

h0: Mean difference = 0 ha: Mean difference != 0

p value = ~0

Reject h0

c: 90% (-2.6, -1.3)

Becuase the premium gas costs more, meaning that it may not be cost effective despite better mileage

h0: Mean 1 = Mean 2 ha: Mean 1 != Mean 2

p value > 20%

Cannot reject null

No evidnce to show improvment. means of each group are greater than paired.

Problem 23

Conditions:

Randomly selected, Indepennt as cars are independent, Normal condition as NPP is suitable striaght.

(131.78, 145.61)

We’re 95% confident that the mean amount of pavement needed to stop is between the interval.

(-62.61, -38.78)

We’re 95% confident that thte true increase in stopping distance is between the invertval.

Problem 24

Conditions:

we assume randomly selected, we assume that 10 stops are less than 10% of population, we see that NPP is pretty straight meaning nearly normal model.

(133.6, 145.1)

We’re 95% confident that the mean amount of pavement needed to stop is between the interval.

(-75.5, -50.4)

We’re 95% confident that thte true increase in stopping distance is between the invertval.

Problem 25

Data is paired by college, paired data

Conditions:

Paired, random colleges, we assume less than 10% of colleges. Remove UC Irvine as outlier.

90% confident that nonresidents pay between 2651 and 3918 dollars more than residents without Irvine.

I agree with assertion–3500 is within interval.