How do you set up this?I am lost

Question

Find an equation for the linear model of the situation below and use it to make a prediction. A train is traveling north at a constant rate. At 3:00 P.M. it is 55 miles north of a city. At 4:15 P.M. it is 80 miles north of the city. If d represents the distance in miles, and t represents the time in hours, how many miles north of the city will the train be at 5:45 P.M.?
MY answer book has - I don'tknow how they came up with these #'s
d=64t+55 d=231 miles

Answer 1

Beats me. I looked at Damon's solution, and 110 miles looks right to me.

Don't know where the 64 comes from, as that does not fit the data.