由题意,
.
x =
2004+2005+2006+2007
4 =2005.5 ,
.
y =
47+45.5+43.5+41
4 =44.25
将(2005.5,44.25)代入
̂
y =
̂
b x+4055.25 ,可得
∧
b =2
∴
̂
y =2x+4055.25
当x=2012时,
̂
y =2×2012+4055.25 =31.25
故答案为:31.25
由题意,
.
x =
2004+2005+2006+2007
4 =2005.5 ,
.
y =
47+45.5+43.5+41
4 =44.25
将(2005.5,44.25)代入
̂
y =
̂
b x+4055.25 ,可得
∧
b =2
∴
̂
y =2x+4055.25
当x=2012时,
̂
y =2×2012+4055.25 =31.25
故答案为:31.25