College Algebra, Chapter 1, 1.7, Section 1.7, Problem 58

The average height of adult males is 68.2 in, and 95% of adult males have height $h$ that satisfies the inequality $\displaystyle \left| \frac{h-68.2}{2.9} \right| \leq 2$
Solve the inequality to find the range of height.
$\displaystyle \left| \frac{h-68.2}{2.9} \right| \leq 2$ model

We have,

$
\begin{equation}
\begin{aligned}
\frac{h-68.2}{2.9} &\leq 2 && \text{and} & - \left( \frac{h-68.2}{2.9} \right) &\leq 2 && \text{Divide each side by -1}\\
\\
\frac{h-68.2}{2.9} &\leq 2 && \text{and} & \frac{h-68.2}{2.9} &\geq -2 && \text{Multiply by } 2.9\\
\\
h - 68.2 &\leq 5.8 && \text{and} & h - 68.2 &\geq -5.8 && \text{Add 68.2}\\
\\
h &\leq 74 && \text{and} & h &\geq 62.4
\end{aligned}
\end{equation}
$


Thus, the range of the height is $62.4 \leq h \leq 74$