Instruction 2-8
the Stem-And-Leaf Display Represents the Number of Times

Instruction 2-8
The Stem-and-Leaf display represents the number of times in a year that a random sample of 100 "lifetime" members of a health club actually visited the facility.
$$\begin{array} { l l } \text { Stem } & \text { Leaves } \\\hline0 & 012222233333344566666667789999 \\1 & 1111222234444455669999 \\2 & 00011223455556889 \\3 & 0000446799 \\4 & 011345567 \\5 & 0077 \\6 & 8 \\7 & 67 \\8 & 3 \\9 & 0247\end{array}$$
-Referring to Instruction 2-8,if a frequency distribution with equal sized classes was made from this data,and the first class was "0 but less than 10",the class midpoint of the third class would be ________.