Consider the Following Frequency Distribution What Is the Cumulative Frequency of the Second Class Interval

Multiple Choice

Consider the following frequency distribution: $$\begin{array} { l c } \text { Class Interval } & \text { Frequency } \\10 \text {-under } 20 & 15 \\20 \text {-under } 30 & 25 \\30 \text {-under } 40 & 10\end{array}$$
What is the cumulative frequency of the second class interval?

A) 25
B) 40
C) 15
D) 50