Measures of the Spread of the Data · Exercise 19

gives the percent of children under five considered to be underweight.

$$\begin{array}{cc}\text{Percent of Underweight Children}& \text{Number of Countries}\\ \text{16–21.45}& \text{23}\\ \text{21.45–26.9}& \text{4}\\ \text{26.9–32.35}& \text{9}\\ \text{32.35–37.8}& \text{7}\\ \text{37.8–43.25}& \text{6}\\ \text{43.25–48.7}& \text{1}\end{array}$$
What is the best estimate for the mean percentage of underweight children? What is the standard deviation? Which interval(s) could be considered unusual? Explain.

Its source prints no answer for this problem, so there's nothing to check against.

OpenStax, Introductory Statistics 2e · §2.7 Measures of the Spread of the Data · Exercise 19