The lengths of pregnancies in a small rural village are normally distributed with a mean of 261 days and a standard deviation of 12 days. In what range would you expect to find the middle 50% of most pregnancies?
Between
and
.

If you were to draw samples of size 37 from this population, in what range would you expect to find the middle 50% of most averages for the lengths of pregnancies in the sample?
Between
and
.