Subtract 80 from each data in a group of data to get a new group of data. If the average of the new group of data is 1.2 and the variance is 4.4, then the average and variance of the original group of data are______ And______ ．

Subtract 80 from each data in a group of data to get a new group of data. If the average of the new group of data is 1.2 and the variance is 4.4, then the average and variance of the original group of data are______ And______ ．

Average. X = 1n (x1 + x2 +...) +xn）=1n[（x1-a）+（x2-a）+… +(xn-a)] + A, the original average of a group of data is 80 + 1.2 = 81.2, its variance remains unchanged, is still 4.4

How does the mean and variance change after subtracting a number from any set of data

The average is the original average minus this number;
Variance is constant!