You can put this solution on YOUR website!
Graph the data using distance east as x axis (start at 0 and go to 75 at least) and temperature as the y axis.
Then see if you can fit a straight line through the data.
If so, then it is a good linear model.
Look at your straight line and read off the value at x=75. That will be the expected temperature at 75 miles east.
Please post another question if you get stuck.
I'll start you off here plotting (0,85.2)