Answer:
The mean = 17.54
Step-by-step explanation:
Form a table as below;
Interval Frequency{f} Midpoint of frequency{x} fx
1-7 19 4 76
8-10 14 9 126
11-15 15 13 195
16-20 20 18 360
21-35 10 28 280
36-50 13 43 559
Sum 91 1596
The mean of grouped data = Sum of { Interval Midpoint * Frequency } /Sum of frequency
The mean= 1596 / 91
The mean = 17.54