Answer: 0.025
Explanation:
Given : A statistics professor plans classes so carefully that the lengths of her classes are uniformly distributed between interval : [48.0 minutes, 53.0 minutes]
Let x be the lengths of her classes that are uniformly distributed between interval : [48.0 minutes, 53.0 minutes].
The probability density function for the given situation :-

The probability that a given class period runs between 51.25 and 51.5 minutes is given by :-
![P(51.25<x<51.5)=\int^(51.5)_(51.255)f(x)\ d(x)\\\\=(1)/(10)\int^(51.5)_(51.25)\ dx\\\\=(1)/(10)[x]^(51.5)_(51.25)\\\\=(1)/(10)(51.5-51.25)\\\\=(1)/(10)(0.25)\\\\=0.025](https://img.qammunity.org/2021/formulas/mathematics/college/wd0mfo9t8kd6qo8qgu3y3zdx1xzy6l0uiq.png)
Hence, the probability that a given class period runs between 51.25 and 51.5 minutes is 0.025 .