A large school district held a district-wide track meet for all high school students. For the 2-mile run, the population of female students participating had a mean running time of 8.8 minutes with standard deviation of 3.3 minutes, and the population of male students participating had a mean running time 7.3 minutes with standard deviation of 2.9 minutes.
Suppose 8 female students and 8 male students who participated in the 2-mile run are selected at random from each population.
Let x-barM represent the sample mean running time for the male students, and let x- barF represent the sample mean running time for the female students. What are the mean and standard deviation of the sampling distribution of the difference in sample means x-barM-x-barF?
a. 0.4 & 4.042.
b. 1.5 & 1.553.
c. 0 -1.5 & 2.413.
d. 1.5 & 2.413.
e. -1.5 & 1.553.