The military is assessing the fitness of new recruits. A drill sergeant randomly selects 10 recruits, and has them run a mile. He then computes the 95% confidence interval for the mean mile time of all recruits. He does it again after 50 runners, after 100 runners, and after 200 runners. We would expect that each time he computes this confidence interval, it will:

Select one:

a.

become narrower

b.

become more Normal

c.

become more uniform

d.

become wider