# math 127

posted by
**marylou**
.

In 2008 ACT,Inc reported that 74% of 1500 randomly selected college freshman rerurned to college the next year. Estimate the national freshman to sophomore retention rate.

a) Verify below the two condition are met for constructing a confidence interval for the population proportion.

b) What is the value of t a/2or z a/2 for 99% confidence interval

c) What is value of the margin of errorfor your interval?