The National Highway Traffic safety Administration reports t

The National Highway Traffic safety Administration reports that the mean number of speeding-related traffic fatalities over the Thanksgiving holiday period from 1994-2003 was 202.7. We conduct a hypothesis test to examine whether the population mean number of such fatalities has decreased.

(a) State the null and alternative hypotheses:

(b) State the Type I error and Type II error for this problem in words.

Solution

a) H0: the population mean remains the same

H1: the population mean has increased

b) If the null hypothesis is true and we reject it, that is if the mean remains the same, but we reject the null hypothesis, then it is type 1 error.

On the other hand, if the population mean has increased, but we accept the null hypothesis, then it is type 2 error.