[SOLVED] Finding the Area under the Curve.

Please help me with this problem. I have a test in the class tomorrow. I already found the height of the distribution by using 1 divided by the total width of the distribution and got 0.5, but from there I'm stuck. Please help.

This is the problem:

A statistics professor plans classes so carefully that the lengths of her classes are uniformly distributed between 50.0 and 52.0 minutes. Find the probability that a given period runs less than 50.75 minutes.

Thank you for any help.

-Sarah (Bigsmile)