Imagine that a researcher wanted to know the average weight

Imagine that a researcher wanted to know the average weight of 5th grade boys in a high school. He randomly sampled 5 boys from that high school. Their weights were: 120 lbs., 99 lbs, 101 lbs, 87 lbs, 140 lbs. What’s the standard error of the mean? (show work)

Solution

Getting the standard deviation of the 5 values,

s = 20.79182532

Thus, the standard error is

SE = s/sqrt(n) = 20.79182532/sqrt(5) = 9.298386958 [ANSWER]