Question: 45
(Choose 1 answer)
A consumer group conducts a study to compare the average miles per gallon (mpg) achieved in road tests of
two popular car brands. A random sample of 5 cars from Brand 1 were tested, yielding sample mean 29.5
mpg and sample standard deviation 7.4 mpg. A random sample of 8 cars from Brand 2 were tested, yielding
sample mean 31.6 mpg and sample standard deviation 8.4 mpg.
Assume that the population variances are equal and that the two populations from which the samples are
drawn are normally distributed. To test the null hypothesis of no difference between the true average miles per
gallon for Brand 1, and the true average miles per gallon for Brand 2, which inferential statistical test is most
appropriate?
A. two-sample independent t-test
B. two-sample z-test
C. two-sample proportion z-test
D. none of the above
