Determine the probability of 22 completed puzzles having an average of 10 minutes or shorter.

Question

Ivy finishes each puzzle with a normal distribution of times where µ=6 minutes or σ=14 minutes.

Answer 1

The mean will be distributed with mean = 6 and standard deviation = 14 / √22

You need p (X<10)

On a TI-84

2ND VARS

normalcdf

lower = -1E99

upper = 10

mean = 6

sd = 14 / √22

paste

0.9099 is the required probability