Question

Consider the population of adult female residents in Melbourne (or Jupiter if you prefer). Our focus is on the population mean height. Let height be called X. Assume we do not know ? (population standard deviation) or the population mean, µ. We take a sample of adult female residents in Melbourne (n=100) and calculate the sample mean height as 70 cm and the sample standard deviation of 25.

i) Test the null hypothesis that µ=120, against the alternative that µ≠120. Use a 5% level of significance. Interpret your results.
ii) Now use a one sided test 5% significance level Ho= µ≥120, H1 = µ <120. Interpret your results.

Answer 1