Aisha runs a tutoring business. With Plan 1, students may choose to pay $24 per hour. With Plan 2, they may follow the plan shown on the graph.

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?

Which expression gives the exact value of x?

The approximate line of best fit for the given data points, y = −2x − 2, is shown on the graph.which is the residual value when x = –2? a)–2 b)–1 c)1 d)2