For a random sample of size n =100 from a normally distributed population has a sample 1. mean of = 20.85 and a sample standard deviation ofs = 13.41. Find a: %3D a) 95% confidence interval for the population mean u Table II Normal Curve Areas .03 .02 .04 .05 .00 .01 .06 .07 .09 .08 Z 0160 0557 .0948 1331 .1700 2054 0080 0478 .0871 .0120 0s17 0910 .0199 0596 0987 .1368 .1736 2088 0000 0398 0793 0239 .0636 .1026 .0040 0438 0832 .0279 67వ .1064 0319 .0714 .1103 .1480 .1844 2190 0359 0753 .1141 .1406 .1772 2123 1293 1664 2019 .1443 .1808 2157 1179 1554 .1915 .1217 1591 .1950 .1255 1628 .1985 .1517 .1879 2224 2486 2517 2823 3106 3365 3599 2257 2580 2881 3159 3413 2549 .2852 3133 3389 3621 2324 2642 2939 3212 3461 2291 2389 2704 2995 3264 .3508 2422 2734 3023 3289 3531 2454 2357 2673 2967 3238 3485 2794 3078 .3340 3577 .2764 3051 3315 3554 2611 2910 3186 3438 bh LO 3830 3790 3980 4147 4292 4418 3810 3749 3944 4115 4265 4394 .3708 3907 4082 4236 A370 .3770 3686 3729 3665 3643 3849 4032 A192 4332 L.1 4015 4177 4319 4441 3997 4162 4306 4429 3925 4099 4251 4382 3962 4131 3888 4066 4222 4357 .3869 .4049 4207 4345 1.2 1.3 L4 4279 4406 1.5 4545 .4633 4706 4767 4535 4625 4699 4761 4812 4505 A599 4678 4744 4525 4616 4693 4495 4591 4671 .4738 4793 4515 4484 4474 4452 4554 4641 A713 4772 4463 1.6 4608 A686 4573 4656 4726 4783 4582 4664 4732 4788 4564 4649 4719 4778 L.7 1.8 4750 4756 19 4817 4803 .4808 4798 2.0 4857 4850 4884 4854 4842 4846 4881 4909 4931 4948 4838 4875 4904 4927 4945 4834 4830 4868 4898 4922 4941 4826 4864 4896 4920 4940 4821 2.1 4890 4916 4936 4952 4887 4913 4934 4951 A878 4906 4929 4946 4871 4901 4925 4943 4861 4893 4918 4938 2.2 2.3 2.4 2.5 .4911 .4932 .4949 4964 .4961 4971 .4979 4985 .4989 4962 4972 .4979 .4985 .4989 4963 4973 4980 4986 4990 4960 .4959 4969 4977 4984 4988 4957 4968 4977 4983 4988 4956 .4955 4966 4975 4982 .4987 .4953 4965 4974 A4981 4987 2.6 4974 .4981 4986 4990 4970 4978 4984 4989 4967 4976 4982 4987 27 28 2.9 3.0 tistical Tables and Formulas (New York: Wiley), 1952. Source: Abridged from Table I of A. Hald,