PPT Slide

On a normal distribution with a mean of 55 and a standard deviation of 2.78, find the percentage of cases between the following raw scores and the mean.

A) 49.3 B) 56.67

First, determine what is known M = 55

SD = 2.78

Formula: z = X - M

SD

You want the percentage between the score and mean.

Next, begin working out the problem (A):

z = 49.3 - 55

2.78

z = - 5.7

2.78

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