Goodness-of-Fit Test · Exercise 31

Read the statement and decide whether it is true or false.

contains information from a survey among 499 participants classified according to their age groups. The second column shows the percentage of obese people per age class among the study participants. The last column comes from a different study at the national level that shows the corresponding percentages of obese people in the same age classes in the USA. Perform a hypothesis test at the 5% significance level to determine whether the survey participants are a representative sample of the USA obese population.

$$\begin{array}{ccc}\text{Age class (years)}& \text{Obese (percentage)}& \text{Expected USA average (percentage)}\\ \text{20–30}& \text{15.0}& \text{32.6}\\ \text{31–40}& \text{26.5}& \text{32.6}\\ \text{41–50}& \text{13.6}& \text{36.6}\\ \text{51–60}& \text{21.9}& \text{36.6}\\ \text{61–70}& \text{21.0}& \text{39.7}\end{array}$$

OpenStax, Introductory Statistics 2e · §11.2 Goodness-of-Fit Test · Exercise 31