Question

The mads scored by the students in a slip test are
given below.x=4,6,8,10,12
f=7,3,5,9,5
Find the standard deviation of the marks​

Answer 1

Given : The marks scored by the students in a slip test are given below ..

x = 4 , 6 , 8 , 10 , 12

y = 7 , 3 , 5 , 9 , 5

To find : The standard deviation of the marks.

solution : mean marks = $\frac{\Sigma fx}{\Sigma f}$

= (4 × 7 + 6 × 3 + 8 × 5 + 10 × 9 + 12 × 5)/(7 + 3 + 5 + 9 + 5)

= (28 + 18 + 40 + 90 + 60)/(29)

= (236)/(29)

≈ 8.14

standard deviation = $\sqrt{\frac{\Sigma f(\bar x-x)^2}{\Sigma f}}$

= √[1/29 {7(8.14 - 4)² + 3(8.14 - 6)² + 5(8.14 - 8)² + 9(8.14 - 10)² + 5(8.14 - 12)²}]

= 2.87347 ≈ 2.9

Therefore standard deviation of the marks is 2.9

Answer 2

Step-by-step explanation:

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