Variance and average

Of the 40 values were calculated average mx = 7.5 and variance sx = 2.25. After the control was found to lack the two items of the values of x41 = 3.8 and x42=7. Correct the above characteristics (mx and sx).

Result

m2 =  7.4
r2 =  2.455

Solution:

Solution in text m2 =
Solution in text r2 =







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