b. Compute the z-scores for the following values of X and locate each on the graph. X Z-score 200 320 220 270 250 Solution First you find the mean of all your values. (252) Next you have to find the standard deviation by subtracting the mean from all of your numbers (200 - 252 = a; 320 - 252 = b; 220 - 252 = c; 270 - 252 = d; 250 - 252 = e). Square and add together all of the numbers you came up with after subtracting the mean from each number (a^2 + b^2 + c^2 + d^2 + e^2 = x). Divide x by one less than the number of items on your list (in this case, you divide x by 4 since you have 5 values listed). After you divide, take the square root of that number and that is your standard deviation (x/4 = S). Finally, to find your Z score, you subtract each number by the mean again and divide it by the standard deviation [(200 - 252)/S *or* a/S if you have been following the variables I\'ve been using.].