I need help with this question ! if someone could also explain what the answer is, that would be awesome.

Idon’t understand this.. will someone ? will mark brainliest along with 20 points.

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?

Tan198=asin164=? how to solve this? ?