Answer: 0.125
Explanation:
Given: A statistics professor plans classes so carefully that the lengths of her classes are uniformly distributed in interval (50,52).
∴ The probability density function of X will be :-

The required probability will be:-
![P(51.25<x<51.5)=\int^(51.5)_(51.25)f(x)\ dx\\\\=(1)/(2)\int^(51.5)_(51.25)\ dx\\\\=(1)/(2)[x]^(51.5)_(51.25)\\\\=(1)/(2)(51.5-51.25)=(0.25)/(2)=0.125](https://img.qammunity.org/2020/formulas/mathematics/college/frlbs442vpnkqh9rmw4871lcd1ukyycxjb.png)
Hence, the probability that a given class period runs between 51.25 and 51.5 minutes =0.125