COMEDK2015MathematicsStatistics

The mean and variance for the data 6,7,10,12 , 13,4,8,12 respectively are

Options

A8, 26.25
B9, 9.25
C8,26.25
D9,9.25

Correct answer

D. 9,9.25

Step-by-step solution

Data is 6,7,10,12,13,4,8,12 Here, n=8 Mean aligned &= 6+7+10+12+13+4+8+12 8 &= 72 8 =9 aligned Now, variance = 1 n x_ i ²-( x )² aligned &= 1 8 [(6)²+(7)²+(10)²+(12)²+(13)² . & .+(4)²+(8)²+(12)² ]-81 &= 1 8 [722]-81=90.25-81=9.25 aligned

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