If we randomly selected 5 meals what is the probability that

If we randomly selected 5 meals, what is the probability that the mean amount of time needed to prepare these 5 meals will be less than 10 minutes?

mean is 10.13

std diviation is .6462

sample size is 100

Solution

Mean = u = 10.13
SD = 0.6462
Sample size = 100
x = 10

z = (x - u) / (SD / sqrt(n))

z = (10 - 10.13) / (0.6462/sqrt(100))

z = -2.011761064685855772206747137109254100897554936552151

We are looking for P(z < -2.011761064685855772206747137109254100897554936552151)

We need this link ----> https://www.easycalculation.com/statistics/p-value-for-z-score.php

Enter z = -2.011761064685855772206747137109254100897554936552151 and we find that
the left tailed value(we check left tailed value because we need for the value to be LESS THAN 10 min)

For z = -2.011761064685855772206747137109254100897554936552151, P = 0.0221

Answer ---> 0.0221