Question

The following list of test scores has an average of 50 and an SD of 10:
39 41 47 58 65 37 37 49 56 59 62 36 48 52 64 29 44 47 49 52 53 54 72 50 50
How many scores really were within 1.25 SDs of average?

Answer 1

Using the given table, it is found that 18 scores were within 1.25 SDs of average.

Which scores are within 1.25 SDs of the average?

The average is of 50 while the standard deviation is of 10, hence:

1.25SD = 1.25 x 10 = 12.5

50 - 12.5 = 37.5

50 + 12.5 = 62.5

Hence, scores between 37.5 and 62.5 were 1.25 SDs of average.

Looking at the table, it is found that 18 scores were within 1.25 SDs of average.

You can learn more about mean and standard deviation at https://brainly.com/question/24663213