In: Statistics and Probability
(estimate) is
an unbiased estimator of
.
Proof: = E(^)=
E(
Ci yi)
= Ci E(yi)
= Ci(
o +
1Xi)
= o
Ci +
1
CiXi equation
1
Now Ci=
=
= 1
= 0
Substituting values of and
in
equation 1
E(o^)=
o
Hence o^ is an unbiased
estimator of
o.
Var(o^)= Var(
)
=
=
=
=
)
=
Note that
Var(o^)
=
Hence the result.