Solution:
Given:
The lengths of a runner's workout have a continuous uniform distribution between 49.29 min and 55.55 min.
To find:
P57
When one workout is randomly selected.
Step-by-step explanation:
Let a =49.29 and b = 55.55
x -uniform (49.29,55.55)
We know that:

Replace a =49.29 and b = 55.55 in the above equation.

Let k be the 57th percentile.
P(x < k) = k × f(x)
Replace P(x<k) =0.57 and f(x)=1/6.26 in the above formula.

Multiply both sides by 6.26


Final answer:
P57 = 3.5682