Measures of the Center of the Data · Exercise 11

We are interested in the number of years students in a particular elementary statistics class have lived in California. The information in the following table is from the entire section.
$$\begin{array}{cccc}\text{Number of years}& \text{Frequency}& \text{Number of years}& \text{Frequency}\\ \text{7}& \text{1}& \text{22}& \text{1}\\ \text{14}& \text{3}& \text{23}& \text{1}\\ \text{15}& \text{1}& \text{26}& \text{1}\\ \text{18}& \text{1}& \text{40}& \text{2}\\ \text{19}& \text{4}& \text{42}& \text{2}\\ \text{20}& \text{3}& & \\ & & & \text{Total = 20}\end{array}$$

What is the IQR?

(a) 8
(b) 11
(c) 15
(d) 35

OpenStax, Introductory Statistics 2e · §2.5 Measures of the Center of the Data · Exercise 11