Please include all required steps and answer(s). And reduced to lowest terms where possible.

the following problems I seem to be stuck help me please. If you can show me your work and Explain (or analyze) the results. It's easier to follow if its like typed like a Microsoft Word document.

1. The final exam scores listed below are fromonesection of MATH 200.How many scores were within one standard deviation of the mean? How many scores were within two standard deviations of the mean?

993486577385919346968879688589

The scores for math test #3 were normally distributed. If 15 students had a mean score of 74.8% and a standard deviation of 7.57, how many students scored above an 85%?

If you know the standard deviation, how do you find the variance?

To get the best deal on a stereo system, Louis called8 out of 20 appliance stores in his neighborhood and asked for the cost of a specific model. Below is the sample data set of prices he collected:

$216$135$281$189$218$193$299$235

Find the standard deviation.