Question

The following data represent the daily rental amount in dollars for a compact automobile charged by two rental car companies, Thrifty and Hertz, in seven locations. Test whether Thrifty is less expensive than Hertz using α = 0.05 Assume the distribution of the differences is normally distributed. (10 points) Thrifty 21.81 17.90 27.98 24.61 21.96 20.90 37.75 Hertz 18.99 19.99 35.99 25.60 22.99 19.99 36.99

Answer 1

The sample data is ( R code)

X1 <- c(21.81 ,17.90, 27.98, 24.61 ,21.96, 20.90, 37.75)
X2 <- c(18.99, 19.99, 35.99, 25.60 ,22.99, 19.99, 36.99)
mean(X1)
sd(X1)
mean(X2)
sd(X2)
length(X1)
length(X2)

The sample means are . The sample standard deviations are . Sample sizes are .

We have to test

Thus the test statistic is

The P-value of the test is

Since , we fail to reject the null hypothesis.

There is no sufficient statistical evidence to support the claim that Thrifty is less expensive than Hertz at .