Exercise 8 Page 694

A two-way table is a frequency table that displays data collected from one source that belongs to two different categories. We want to find the relative frequency of students that $\text{studied}$ $\text{independently}$ $\text{for}$ $\text{more}$ $\text{than}$ $2$ $\text{hours}$ to the total number of students who $\text{studied}$ $\text{independently}.$ We will start by looking at the given table.

	Studies Less Than $2$ Hours	Studies More Than $2$ Hours
Studied Independently	$12$	$4$
Studied with a Study Group	$8$	$11$

We can see in the table that there are $4$ students who studied independently for more than $2$ hours. Now we will calculate the total number of students who $\text{studied}$ $\text{independently}.$ To do so, we can add the number of students who studied independently for less than $2$ hours to the number of students that $\text{studied}$ $\text{independently}$ $\text{for}$ $\text{more}$ $\text{than}$ $2$ $\text{hours.}$ Let's do it! Finally, we can find the the missing frequency. To do so, we calculate the ratio of the number of students who $\text{studied}$ $\text{independently}$ $\text{for}$ $\text{more}$ $\text{than}$ $2$ $\text{hours}$ and the total number of students who $\text{studied}$ $\text{independently}.$ The frequency of students that $\text{studied}$ $\text{independently}$ $\text{for}$ $\text{more}$ $\text{than}$ $2$ $\text{hours}$ to the total number of students who $\text{studied}$ $\text{independently}$ is equal to $0.25.$ This result corresponds to answer C.