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?
Write a ratio and a percent for the shaded area. it is 3x3 and 5x5 grid there is 6 shaded out of a. 6 over 25 , 30% b. 3 over 50 , 6% c.6 over 25 , 24% d. 3 over 10 , 30%