Someone me pronto i need these answers very quickly also

Acircle has a diameter will endpoints of (-2,8) and (6, 4). what is the center of the circle

What is the range? can’t seem to find it out

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?