I am confused on the answer for Q2 part A.
Petra Munzi wants to know how value managers performed last year. Munzi
estimates that the population cross- sectional standard deviation of value manager returns is 4 percent and assumes that the returns are independent across
A. Munzi wants to build a 95 percent confidence interval for the mean return.
How large a random sample does Munzi need if she wants the 95 percent
confidence interval to have a total width of 1 percent?
I am confused as to how they arrived at the highlighted formula?
Could someone please explain this to me?