The z value that corresponds to a probability of 0.80 was found to be 0.84, the mean was given to be = 14.4%, and the standard deviation was given to be = 4.4%. Substitute these values into the formula derived to calculate x, rounding to two decimal places. x = z + = 0.84(4.4) + =1 Therefore, a return of % or higher will put a domestic stock fund in the top 20%.