Chapter 13, Problem 24RE

To determine

To calculate: Find the probability of $x$ -value from the distribution.

Answer to Problem 24RE

The correct answer is $p(x\ge 25)=0.772$ .

Explanation of Solution

Given information: A normal distribution has a mean of $33$ and a standard deviation of $4$ is given.

Calculation: First find $z$ -score that corresponds to an $x$ -valueof $25$ .

  $z=\frac{x-\overline{x}}{\sigma }=\frac{25-33}{4}=-2$

We use the standard normal table to find,

  $\begin{array}{l}p(x\ge 25)\approx p(z\ge -2)=1-p(z\le -2)\\ =1-0.228=0.772\end{array}$

Thus, the correct answer is $0.772$ .