Computing Z-Scores #2

#1
The following data represent the number of inches of rain in Chicago, Illinois, during the month of April for 20 randomly selected years.

2.47, 3.97, 3.94 ,4.11, 1.14, 4.02, 3.41, 1.85, 5.22, 0.97, 6.14, 2.34, 3.48, 4.77, 2.78, 4.00, 6.28, 5.50, 7.69, 5.79

Compute the z-score corresponding to the rainfall in 1971, 0.97 inches. Interpret this result.
 

JohnM

TS Contributor
#2
Compute the mean and standard deviation of the data set, then the z score for 0.97:

Z = (0.97 - u) / s

u = mean of the data set
s = standard deviation of the data set

The interpretation would be whether it was above or below average, and how many standard deviations it is away from the mean.