Chapter 8.5, Problem 33E

To determine

To explain the meaning of the integral ${\displaystyle \underset{100}{\overset{800}{\int }}f(t)dt}$

Explanation of Solution

Given information: $f(t)$ be the probability density function for the lifetime of a certain type of light bulb.

Calculation :

The integral gives the percentage of the life of light bulb between 100 hours and 800 hours by calculating the area of $f(t)$ between 100 and 800.