# STAT MOD3.docx - 1 The final exam scores listed below are...

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1. The final exam scores listed below are from one section 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? 99 34 86 57 73 85 91 93 46 96 88 79 68 85 89 Based on the empirical rule mentioned, this means that 10 scores falls with one standard deviation, and 14 falls within 2 standard deviations. 2. 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%? z-score 85-74.8/7.57=1.347 1-0.9111=0.0889 15*0.0889=1.33 So 1 student would have scored above a 85% 3. If you know the standard deviation, how do you find the variance? square the standard deviation. 4. To get the best deal on a stereo system, Louis called 8 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.