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 Can you write more clearly? I read a lot of similar answers, but I can't understand them Well, I admit that I'm not good at understanding

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 Can you write more clearly? I read a lot of similar answers, but I can't understand them Well, I admit that I'm not good at understanding

（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=3n
2(x1+x2+...+xn)=16n 2(x1+3/2+x2+3/2+...+xn+3/x)/n=19
((2x1+3-19)²+(2x2+3-19)²+.+(2xn+3-19)²)/n
=(4(x1-8)²+4(x2-8)²+...+4(xn-8)²)/n
=4[(x1-8)²+(x2-8)²+...+(xn-8)²]/n
=12 standard deviation = 12 under root = 2 under root 3