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From the graphing calculator,
unbiased estimate of population mean
unbiased estimate of population variance
We assume that 2.31 is a good estimate of the unknown population variance.
We assume the distance travelled per litre of fuel by a car is independent of another car.
Under , perform a left-tailed T-test.
Using the graphing calculator, p-value , thus we do not reject .
There is insufficient evidence at 5% significance level to say that the distance travelled per litre of fuel is too high.
This is a fairly manageable question that should be attempted. The only issue is probably with the assumption part. Students cannot use their regular “assume population mean followed a normal distribution” assumption since the question stated it. So they need to be more creative. As to what constitutes a good estimate, we consider if they are consistent and unbiased.
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