The average return for large-cap domestic stock funds over the three years 2009–2011 was 14.3% (AAII Journal, February, 2012). Assume the three-year returns were normally distributed across funds with a standard deviation of 4.3%.

a. What is the probability an individual large-cap domestic stock fund had a three-year return of at least 20%?

b. What is the probability an individual large-cap domestic stock fund had a three-year return of 10% or less?

c. How big does the return have to be to put a domestic stock fund in the top 10% for the three-year period?