Me answer this. my professor taught us this but with the formula on the right.

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?

Mackenzie needs to determine whether the rectangles are proportional. which process could she use? check all that apply.

As a salesperson you get $50/day and $3.60/each sales you make. if you want to make $60 in one day, how many sales would you need need to make ? a 3b 4c 5d 6 show work.