Question

A banana has a mean weight of 120 grams with a standard deviation of 3 grams. How many standard deviations below the mean is a banana that is 111 grams?

Answer 1

$Z=\frac{X-\mu}{\sigma}$

$=\frac{111-120}{3}=-3$

A banana that is 111 is 3 standard deviations below the mean.