A random sample of 11 Items Is drawn from a population whose standard devlation Is unknown. The sample mean Is =810 and the sample standard devlation Is s= 20. Use Appendix D to find the values of...

Extracted text: A random sample of 11 Items Is drawn from a population whose standard devlation Is unknown. The sample mean Is =810 and the sample standard devlation Is s= 20. Use Appendix D to find the values of Student's t (a) Construct an Interval estimate of u with 98% confidence. (Round your answers to 3 decimal places.) The 98% confidence interval is from to (b) Construct an Interval estimate of u with 98% confidence, assuming that s= 40. (Round your answers to 3 mal places.) The 98% confidence interval is from to (c) Construct an Interval estimate of u with 98% confidence, assuming that s = 80. (Round your answers to 3 decimal places.) The 98% confidence interval is from to