Measures of the Center of the Data · Exercise 8

Scientists are studying a particular disease. They found that countries that have the highest rates of people who have ever been diagnosed with this disease range from 11.4 percent to 74.6 percent.

$$\begin{array}{cc}\text{Percentage of Population Diagnosed}& \text{Number of Countries}\\ \text{11.4–20.45}& \text{29}\\ \text{20.45–29.45}& \text{13}\\ \text{29.45–38.45}& \text{4}\\ \text{38.45–47.45}& \text{0}\\ \text{47.45–56.45}& \text{2}\\ \text{56.45–65.45}& \text{1}\\ \text{65.45–74.45}& \text{0}\\ \text{74.45–83.45}& \text{1}\end{array}$$

(a) What is the best estimate of the average percentage affected by the disease for these countries?
(b) The United States has an average disease rate of 33.9 percent. Is this rate above average or below?
(c) How does the United States compare to other countries?

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

OpenStax, Statistics · §2.5 Measures of the Center of the Data · Exercise 8