work: Chapter 8 (Sections 8.1 through 8.5) i Saved Help A random sample of 16 items is drawn from a population whose standard deviation is unknown. The sample mean is x = 890 and the sample standard deviation is s = 15. Use Appendix D to find the values of Student's t. (a) Construct an interval estimate of / with 95% confidence. (Round your answers to 3 decimal places.) The 95% confidence interval is from to ok Int ences (b) Construct an interval estimate of / with 95% confidence, assuming that s= 30. (Round your answers to 3 decimal places.) The 95% confidence interval is from to (c) Construct an interval estimate of / with 95% confidence, assuming that s = 60. (Round your answers to 3 decimal places.) The 95% confidence interval is from to Mc Graw Hill