First, we need to find the total frequency. This is given by adding all the given frequencies. That is,
[tex]\begin{gathered} f_{\text{total}}=4+6+7+5 \\ f_{\text{total}}=22 \end{gathered}[/tex]
and the relative frequency is the division of the frequency of the corresponding interval by the total frequency,
[tex]f_{\text{rel}}=\frac{f_{\text{ interval}}}{f_{total}}[/tex]
Therefore, the answers are:
a) 4/22 but written in simple form:
[tex]\frac{2}{11}[/tex]
b)
[tex]\frac{5}{22}[/tex]
