Assume the random variable X is normally distributed with mean 50 and standard deviation 7 . Find the 67th percentile

Answer 1

using the empircal rule 68% fall withing 1 standard deviation from the mean

43 < x < 57 is 68%

36 < x < 64 is 95%

0 < x < 64 is 50%+95/2% = 50+47.5 = 97.5%

0 < x < 68 is slightly more than 97.5%

use z score tables or z calucators to get more accurate estimates

99.494% from one online z calculator