11. Use the distance formula to find the unknown value. d = 480 mi, r = ?,1 = 3 h
a. 164 mi/h
b. 158 mi/h
c. 162 mi/h
d. 160 mi/h

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?