Page 669 independent practice : ccc

15 points ! ~ see if you know the answer to both you!

When i add money am i supposed to make it like this 7+12 or 7.00+12.00 because i got 19 dollars for my answer

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?