Q. In the data set below, what is the variance?2,9,6,8,8,4,5If the answer is a decimal, round it to the nearest tenth.variance (σ2): _____
Calculate Variance: Now, let's do the variance thing.We need to sum up each (number−mean)2.So, (2−6)2+(9−6)2+(6−6)2+(8−6)2+(8−6)2+(4−6)2+(5−6)2That's (−4)2+(3)2+(0)2+(2)2+(2)2+(−2)2+(−1)2Which is 16+9+0+4+4+4+1Sum = 38
Sum of Squares: Finally, divide that sum by the number of data points to get the variance.Variance=7SumVariance=738Variance=5.428571…Round it to the nearest tenth and we get 5.4
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