The manufacturer of a gasoline additive claims that the use of additive increases
gasoline mileage. A random sample of eight cars were selected and these cars were
driven for one week without petrol additive and then for one week with petrol
additive. The following gives the miles per liter for these cars without and with
petrol additive.
Car 1 2 3 4 5 6 7 8
Without 24.30 28.23 18.41 20.53 20.24 21.36 22.38 20.51
With 24.43 28.32 18.58 20.46 20.27 21.41 22.38 20.61
a) Calculate the differences of kilometers per liter between cars without and
with petrol additive.
b) Calculate the mean and the standard deviation for the pairs of data.
c) Test at the 5% significance level if there is a mean difference of miles per
liter.
gasoline mileage. A random sample of eight cars were selected and these cars were
driven for one week without petrol additive and then for one week with petrol
additive. The following gives the miles per liter for these cars without and with
petrol additive.
Car 1 2 3 4 5 6 7 8
Without 24.30 28.23 18.41 20.53 20.24 21.36 22.38 20.51
With 24.43 28.32 18.58 20.46 20.27 21.41 22.38 20.61
a) Calculate the differences of kilometers per liter between cars without and
with petrol additive.
b) Calculate the mean and the standard deviation for the pairs of data.
c) Test at the 5% significance level if there is a mean difference of miles per
liter.