Question 1164665
half-interval is z(0.99)*sigma/sqrt(n)
=2.328*69/sqrt(50)
=22.72
so the interval is (151.8, 197.2)

We don't know the true mean, but we are very confident, 98% confident, that it lies in the interval we have chosen. Another way of stating this is if we took 100 samples of 50 from this group, 98 of them would have a mean in this interval.