If sample X1 + 2, X2 + 2 If the average of XN + 2 is 10 and the variance is 3, then the sample 2x1 + 3, 2x2 + 3 The average value of 2xn + 3 is () and the variance is () standard deviation

If sample X1 + 2, X2 + 2 If the average of XN + 2 is 10 and the variance is 3, then the sample 2x1 + 3, 2x2 + 3 The average value of 2xn + 3 is () and the variance is () standard deviation

（X1+2,X2+2,… Xn+2)/n=10 (x1+x2+...+xn)=10n-2n=8n ((x1+2-10)²+(x2+2-10)²+.+(xn+2-10)²)/n=3 (x1+2-10)²+(x2+2-10)²+.+(xn+2-10)²=3n2(x1+x2+...+xn)=16n 2(x1+3/2+x2+3/2+...+xn...

Known data x1, X2 The average of... Xn is 6, then the data 2x1 - 1, 2x2 - 1 The average of.. 2xn - 1 is

2X1 -1,2X2 -1,… . the average of 2xn - 1 = 2 times (x1, X2,...) ..xn)-n=12-n /n=11

The average of a set of data x1, x2.xn is 3
1, find the average of data x1-2, x2-2, x3-2.xn-2
2, find the average of data 3x1, 3x2,. 3XN
3, find the average of data 3x1-2,3x2-2.3xn-2

If the average of sample x1, X2,..., xn is a and the variance is m, then the average of sample a * X1 + B,..., a * xn + B is a * a + B and the variance is a ^ 2 * M;
answer
1、1
2、9
3、7
The average number of x1, x2.xn is 3, that is, 3 = (x1 + x2 +... + xn) / n
And ((x1-2) + (x2-2) +. + (xn-2)) / N = (x1 + x2 +... + xn) / n-2N / N = 3-2 = 1
(3x1+3x2+...+3xn)/n=3(x1+x2+...+xn）/n=9
((3x1-2)+(3x2-2)+...+(3xn-2))=(3x1+3x2+...+3xn)/n-2n/n=9-2=7

If sample X1 + 1, X2 + 1, X3 + 1 The average of XN + 1 is 9, the variance is 3, then the sample X1 + 2, X2 + 2, X3 + 2 The mean of XN + 2 is and the variance is

Mean 10, variance 3