Question

Scores on a test are normally distributed with a mean of 63.2 and a standard deviation of 11.7. Find
`P_(81)` , which separates the bottom 81% from the top 19%.

Answer 1

P81 = Mean + z * Standard deviation , Where Z is critical value at 81% confidence level.

= 63.2 + 0.8779 * 11.7 ( Z critical value calculated from Z table)

= 73.47