Chapter 8.8, Problem 75E

(a)

To determine

To graph: The integrand ${\displaystyle {\int }_{72}^{\infty }\frac{1}{3\sqrt{2\pi }}{e}^{\raisebox{1ex}{${}^{-{\left(x-69\right)}^2}$}\!\left/ \!\raisebox{-1ex}{$18$}\right.}dx}$ using the graphing utility and to verify that area between x-axis and the integrand is 1.

(b)

To determine

To calculate: The approximate value of the functions $P\left(72\le x<\infty \right)$ using a graphing calculator.

(c)

To determine

To calculate: The value offunction $0.5-P\left(69\le x\le 72\right)$ using a graphing calculator.