In 2016, it was reported that 6% of all first-time mothers were 19 years old. Suppose a sample of 400 new mothers is chosen.

Find the probability that the proportion of a sample of 400 first-time mothers that are 19 years old is between than 6.5% and 7.5%.

Find the proportion of a sample of 400 first-time mothers that are 19 years old above which 15% of all proportions of samples of 400 first-time mothers that are 19 years old fall