In: Statistics and Probability
5
Which analysis tool that we studied (from the bulleted list below) should one use for each situation listed in a through d below? Also, state the null and alternative hypothesis for each situation.
a. Testing to see if a brand of tires marketed as lasting 60,000 miles does last 60,000 miles. Your sample size is 100 tires.
b. Testing to see if the failures recorded for these tires follow an exponential distribution.
c. Testing to see if samples of Firestone and Goodyear 60,000-mile tires have the same life. Your sample size is 15 Firestone and 20 Goodyear tires.
d. Testing two brands of tires to see if the age of the driver affects the number of gallons of gas used on a 500-mile trip for five different age groups of drivers.
Choose the best tool to apply to each test (a-d) from the list below.
Z-test / Normal distribution one sample versus threshold(s)
Z-test comparison of two samples T-Test one sample versus threshold(s)
T-test Two Sample assuming unequal variances
T-test Paired data (dependent samples)
Binomial test of one proportion versus threshold(s)
Binomial Test of two proportions
Chi-Square Contingency Table
Chi-Square Goodness of Fit
a. Testing to see if a brand of tires marketed as lasting 60,000 miles does last 60,000 miles. Your sample size is 100 tires.
ANSWER: Z-test / Normal distribution one sample versus threshold(s). Hypotheses are:
b. Testing to see if the failures recorded for these tires follow an exponential distribution.
ANSWER : Chi-Square Goodness of Fit
H0 : The failures recorded follows exponential distribution
H1 : The failures recorded does not follow exponential distribution
c. Testing to see if samples of Firestone and Goodyear 60,000-mile tires have the same life. Your sample size is 15 Firestone and 20 Goodyear tires.
ANSWER : T-test Two Sample assuming unequal variances. Hypotheses are :-
d. Testing two brands of tires to see if the age of the driver affects the number of gallons of gas used on a 500-mile trip for five different age groups of drivers.
ANSWER: Chi-Square Contingency Table . Hypotheses are :