Answer:
Interval $11 - $15 = 0.2
Explanation:
Sum of frequency, Σf = (8+6+4+2+4+6+2) = 32
Relative frequency = f / Σf
Interval :
1 - 5 = 8 / 20 = 0.4
6 - 10 = 6 / 20 = 0.3
11 - 15 = 4 / 20 = 0.2
16 - 20 = 2 / 20 = 0.1
21 - 25 = 4 / 20 = 0.2
26 - 30 = 6 / 20 = 0.3
31 - 35 = 2 / 20 = 0.1