Q. In the data set below, what is the variance?5,2,7,7,5,8,8If the answer is a decimal, round it to the nearest tenth.variance (σ2): _____
Calculate Squared Differences: Now that we have the mean, we calculate the squared differences from the mean for each data point.(5−6)2+(2−6)2+(7−6)2+(7−6)2+(5−6)2+(8−6)2+(8−6)2= (−1)2+(−4)2+(1)2+(1)2+(−1)2+(2)2+(2)2= 1+16+1+1+1+4+4= 28
Find Variance: Finally, we divide the sum of squared differences by the number of data points to find the variance.Number of data points N=7Variance σ2=NΣ(xi−μ)2σ2=728σ2=4Since the variance is a whole number, there is no need to round to the nearest tenth.
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