Mary is planning to buy a mobile phone that costs $500. A salesperson at the store informs her about four different installment plans that she can choose from. plan A: a down payment of $50 and monthly payments of $40 for 12 months
plan B: a down payment of $100 and monthly payments of $80 for 6 months
plan C: no down payment and monthly payments of $60 for 12 months
plan D: no down payment and monthly payments of $100 for 6 months

Which plan will have the highest finance charge?

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.