Question

Solve the following using the t-distribution table:
A random sample of 15 heat pumps of a certain type yielded the following observations on lifetime (in years): 2.0, 1.3, 6.0, 1.9, 5.1, 0.4, 1.0, 5.3, 15.7, 0.7, 4.8, 0.9, 12.2, 5.3, 0.6

a)For obtaining a 95% CI for expected (true average) lifetime, what will be the maximum possible difference between sample mean and true mean.

b) Obtain a 95% CI for expected (true average) lifetime.

Answer 1

a) The maximum possible difference between sample mean and true mean = Margin of error = 2.488

b) a 95% CI for expected (true average) lifetime = (1.73, 6.70)