Suppose that the time X that an experimental engine will operate
with 1 gallon of a certain kind of fuel has a normal distribution,
that is, X - N(µ,o2 ). Test runs with five models of this engine
showed that they operated, respectively, for 21, 19, 23, 18, and
19 min with this kind of fuel.
(a) What is the BLUE estimate of µ?
(b) What is the value of the sample standard deviation s?
(c) Find a 95% confidence interval for µ.
(d) Based on the data given would one accept the null hypothesis
H0 : µ = 23 (versus H1 : µ f 23) at significance level
a = 0.05?