Below Are Income Data for Individuals Who Participated in a Recent

Short Answer

Below are income data for individuals who participated in a recent study.
This data set contains information about the number of hours safe students studied before taking a recent exam. Using this information, answer questions.
$$\begin{array} { c c } \hline \text { Income } & f \\\hline 100000 - 109999 & 9 \\90000 - 99999 & 12 \\80000 - 89999 & 33 \\70000 - 79999 & 21 \\60000 - 69999 & 56 \\50000 - 59999 & 24 \\40000 - 49999 & 19 \\30000 - 39999 & 42 \\20000 - 29999 & 17 \\10000 - 19999 & 6 \\\hline\end{array}$$ What is the mean?