Answer:
The standard deviation is 16.08.
Explanation:
Mid point, (0+9)/2=4.5
(10+19)/2=14.5
(20+29)/2=24.5
(30+39)/2=34.5
(40+49)/2=44.5
(50+59)/2=54.5
Mean = [(4×4.5)+(3×14.5)+(6×24.5)+(3×34.5)+(5×44.5)+(9×54.5)] / (4+3+6+3+5+9)
Mean = (18+43.5+147+103.5+222.5+490.5) / 30
= 1025 / 30
Mean = 34.17
Sum of square deviation= 1106.81+914.79+634.14+0.9192+1099.25+3783.41
= 7749.41
Standard deviation= √(7749)/30
=√258.3137
= 16.08