9.57 A financial analyst is investigating the return rate of mutual funds. He claims that mutual funds have a return rate of 0.10 per annum with a population standard deviation of no more than 0.13. A random sample of annual return rates for eight mutual funds are recorded, a 8

i=1 xi = 1.2 and a 8

i=1 1xi - x22 = 0.05 where xi is the annual return rate in 100%, and the population distribution can be assumed to be normal.

Test, at the 5% level, the null hypothesis that the population mean for mutual funds’ annual return rate is more than 0.10.