Question

Suppose a survey of 2,718 medical school interns found their average age to be 28.0 years, with standard deviation 3.7 years. (a) The distribution of ages is not normal. Will the distribution of sample mean, x, have an approximate normal shape? Yes No (b) If we standardize with sample standard deviation s instead of population standard deviation o, will the standardized sample mean follow an approximate z distribution? Yes No (c) Report an approximate 95% confidence interval for population mean age of interns. (Round your answers to two decimal places.) (d) Use your confidence interval to report which of these are plausible values for population mean age. (Select all that apply.) 27.9 28.0 28.1 28.2 30.0 (e) Find the value of standardized sample mean, if population mean is 30. (Round your answer to one decimal place.) (f) Based on the standardized value of 28, can we say 30 is a plausible value for the population mean age if sample mean is 28? Yes No (g) If we were to carry out a formal test, how should the alternative hypothesis be written? Ha: x+28 Ha: 11 + 28 Ha: x = 28 Ha: <28 Ha: x + 30 Hair + 30 Ha: x < 30 Ha: p < 30 (h) Based on your confidence interval in part (c), would you reject the null hypothesis in favor of the alternative? Yes No Need Help? Read It Tak to a Tutor

Answer 1