Find the value of x and y using the diagram below:

What is the standard deviation of the following data set rounded to the nearest tenth? 3, 17, 18, 15, 12, 21, 9

The distribution of the amount of money spent by students for textbooks in a semester is approximately normal in shape with a mean of $235 and a standard deviation of $20. according to the standard deviation rule, how much did almost all (99.7%) of the students spend on textbooks in a semester?

Steve had 48 chocolates but he decided to give 8 chocolats to each of his f coworkers. how many chocolates does steve have left