Why do certificates of deposit tend to offer better interest rates than money market accounts? a. certificates of deposit involve a longer time commitment than money market accounts, so they carry a greater return. b. certificates of deposit are only available to the bank’s most proven and valuable customers, so the bank can afford to give a greater interest rate on them. c. they do not offer a better interest rate. money market accounts tend to have the best interest rates of any bank deposit. d. money market accounts invest your money but sometimes lose some of it, so the lower interest rate pays for the difference.

According to a research study, parents with young children slept 6.4 hours each night last year, on average. a random sample of 18 parents with young children was surveyed and the mean amount of time per night each parent slept was 6.8. this data has a sample standard deviation of 0.9. (assume that the scores are normally distributed.) researchers conduct a one-mean hypothesis at the 5% significance level, to test if the mean amount of time parents with young children sleep per night is greater than the mean amount of time last year. the null and alternative hypotheses are h0: μ=6.4 and ha: μ> 6.4, which is a right-tailed test. the test statistic is determined to be t0=1.89 using the partial t-table below, determine the critical value(s). if there is only one critical value, leave the second answer box blank.