The lengths of a professor's classes has a continuous uniform distribution between 49.2 min and 55.5 min. If one such class is randomly selected, find the probability that the class length is more than 53.1 min. PX < 53.1)

And

Step-by-step explanation:

Let X the random variable who represent the  lengths of a professor's classes and we know that the distribution for X is given by:

And for this case we want to find the following probability:

We can use the cumulative distribution function given by:

And if we use this formula and the complement rule we got :

And

arc length = radius * x ( in radians)

6 * pi = 18 * x

divide by 18 on each side

6 pi / 18 = x

pi/3 = x

the angle is pi / 3 radians

or   60 degrees