Find the population standard deviation of the following frequency distribution.
Score Frequency
1 9
2 15
3 6
total=30
so, 1*9+2*15+3*6=57
57/30=1.9
and, 9(1-1.9)^2+15(2-1.9)^26(3-1.9)^2=14.7
14.7/30=sqr.49 sqr.49 is my answer, list of possible answers are -
1.sqr0.49
2.sqr1.9
3.sqr2.0
4.sqr2,2
thanks for checking
