1. what are the mean and standard deviation for this distribution of weekly take-home pay amounts?

2. what percentage of the pay amounts lie within 1 standard deviations of the mean?

3. what percentage of the pay amounts lie within 2 standard deviations of the mean?

4. what percentage of the pay amounts lie within 3 standard deviations of the mean?

5. what is the range of the pay amounts?

1 answer

What distribution?

Find the mean first = sum of scores/number of scores

Subtract each of the scores from the mean and square each difference. Find the sum of these squares. Divide that by the number of scores to get variance.

Standard deviation = square root of variance

http://en.wikipedia.org/wiki/File:The_Normal_Distribution.svg