Students from four classes are in talent show. A. There are 28 students in Ms. Fiona’s class. The ratio of her student who are in the talent show to those who are not in the talent show is 2:5. How many of Ms. Fiona's students are in the talent show?

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?