Suppose the expected cost of a production run is related to the size of the run by the equation y 5 4000 1 10x. let y denote an observation on the cost of a run. if the variables’ size and cost are related according to the simple linear regression model, could it be the case that psy . 5500 when x 5 100d 5 .05 and p(y . 6500 when x 5 200) 5 .10? explain.

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.