I think the correct answer from the choices listed above is the third option. <span>If a statistic used to estimate a parameter is such that the mean of its sampling distribution is equal to the actual value of the parameter, then it is a biased estimator. Hope this answers the question.
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Answer:
We have to find the 90% confidence interval for the mean
Given sample size
Sample mean
Population standard deviation
Here the confidence level is 90% then
And
The 90% confidence interval is
Here is the critical value at 0.05
From the tables
Now the 90% confidence interval is =
=
=(3840.44, 4133.56)
Hence the 90% confidence interval for the mean is (3840.44, 4133.56)
The average height of the fence is 2 m; its length is 20π m. So, its 2-sided area is
A = 2*(2 m)*(20π m) = 80π m² ≈ 251 m²
At 1 L/(100 m²), it will take 2.51 L of paint to paint both sides.
