Question

Calculate standard deviation from the data on marks obtained by 10 students :
33 , 40 , 59 , 60 , 64 , 70 , 79 , 85 , 90 , 95

Answer 1

Assumed mean = 70
`sigma = sqrt((sum x^(2))/(N) - ((sumx)/(N))^(2)) = sqrt((3857)/(10) - ((-25)/(10))^(2))`
= `sqrt(385*7 - 6*25 )`
`= sqrt(379*45) = 19*48` marks approx .