Chapter 11 Data Analysis and Statistics - 11.3 Use Normal Distributions - 11.3 Exercises - Problem Solving - Page 761: 31

$16\%$

$\text{z-score}=\frac{\text{data item-mean}}{\text{standard deviation}}$ $|\frac{5-4.6}{0.4}|=1$ The normal distribution is symmetric about the mean. Thus, using the 68-95-99.7 rule and the graph we get: $P( x\geq\overline{x}+\sigma)=313.5\%+2.35\%+0.15\%=16\%$