Find the Mean of the Data Summarized in the Given

Multiple Choice

Find the mean of the data summarized in the given frequency distribution.
-The highway speeds of 100 cars are summarized in the frequency distribution below. Find the mean speed. $$\begin{array} { r | r } \text { Speed (mph) } & \text { Cars } \\\hline 30 - 39 & 3 \\40 - 49 & 17 \\50 - 59 & 51 \\60 - 69 & 16 \\70 - 79 & 13\end{array}$$

A) 59.2 mph
B) 54.5 mph
C) 62.0 mph
D) 56.4 mph