我正在为决赛做研究，但无法解决以下问题：
X1 and X2 are random variables that satisfy `E[X1]=E[X2]=μ` and `Var[X1]=Var[X2]=1.`
Specify the range for μ so that the point estimate `μ1 = ((X1 + X2)/3) + 3`
has a lower mean squared error than the point estimate `μ2 = (X1 + X2)/2 ?`
请帮助