Question

An industrial engineer concerned with service at a large medical clinic recorded the duration of time from the time a patient called until a doctor or nurse returned the call. A sample of size 180 calls had a mean of 1.65 hours and a standard deviation of 0.82.

a) Obtain a 95% confidence interval for the population mean of time to return a call.

c) Perform a test (using critical value approach) with the intention of establishing that the mean time to return a call is greater than 1.5 hours. Use α = 0.05. Also confirm your decision using pvalue approach.

d) In light of your conclusion in part (a), what error could you have made? Explain in the context of this problem.

Answer 1