sample of 20

mean hours of movies watched per month was 80 hrs with 7 hr standard deviation

a. develop a 98% confidence interval for population mean

b. develop a 98% confidence interval for population standard deviation

c. if the sample was 150 households how would you find the confidence intervals for population mean and population sd?

d. increasing the sample size would affect confidence intervals how? would it make interval larger, smaller, same and why?

Use following charts if needed:

Upper Tail Areas (Q) Degrees of Freedom 0.995 0.99 0.975 0.95 0.90 0.75 0.25 0.10 0.05 0.025 0.01 0.005 0.001 0.004 0.016 0.102 1.323 2.706 3.841 5.024 6.635 7.879 0.010 0.020 0.051 0.103 0.211 0.575 2.773 4.605 5.991 7.378 9.210 10.597 0.072 0.115 0.216 0.352 0.584 1.213 4.108 6.251 7.815 9.348 11.345 12.838 0.207 0.297 0.484 0.711 1.064 1.923 5.385 7.779 - 9.488 11.143 13.277 14.860 0.412 0.554 0.831 1.145 1.610 2.675 6.626 9.236 11.071 12.833 15.086 16.750 0.676 0.872 1.237 1.635 2.204 3.455 7.841 10.645 12.592 14.449 16.812 18.458 0.989 1.239 1.690 2.167 2.833 4.255 9.037 12.017 14.067 16.013 18.475 20.278 1.344 1.646 2.180 2.733 3.490 5.071 10.219 13.362 15.507 17.535 20.090 21.955 1.735 2.088 2.700 3.325 4.168 5.899 11.389 14.684 16.919 19.023 21.666 23.589 10 2.156 2.558 3.247 3.940 4.865 6.737 12.549 15.987 18.307 20.483 23.209 25.188 11 2.603 3.053 3.816 4.575 5.578 7.584 13.701 17.275 19.675 21.920 24.725 26.757 12 3.074 3.571 4.404 5.226 6.304 8.438 14.845 18.549 21.026 23.337 26.217 28.299 13 3.565 4.107 5.009 5.892 7.042 9.299 15.984 19.812 22.362 24.736 27.688 29.819 14 4.075 4.660 5.629 6.571 7.790 10.165 17.117 21.064 23.685 26.119 29.141 31.319 15 4.601 5.229 6.262 7.261 8.547 11.037 18.245 22.307 24.996 27.488 30.578 32.801 16 5.142 5.812 6.908 7.962 9.312 11.912 19.369 23.542 26.296 28.845 32.000 34.267 17 5.697 6.408 7.564 8.672 10.085 12.792 20.489 24.769 27.587 30.191 33.409 35.718 18 6.265 7.015 8.231 9.390 10.865 13.675 21.605 25.989 28.869 31.526 34.805 37.156 19 6.844 7.633 8.907 10.117 11.651 14.562 22.718 27.204 30.144 32.852 36.191 38.582 20 7.434 8.260 9.591 10.851 12.443 15.452 23.828 28.412 31.410 34.170 37.566 39.997 21 8.034 8.897 10.283 11.591 13.240 16.344 24.935 29.615 32.671 35.479 38.932 41.401 22 8.643 9.542 10.982 12.338 14.042 17.240 26.039 30.813 33.924 36.781 40.289 42.796 23 9.260 10.196 11.689 13.091 14.848 18.137 27.141 32.007 35.172 38.076 41.638 44.181 24 9.886 10.856 12.401 13.848 15.659 19.037 28.241 33.196 36.415 39.364 42.980 45.559 25 10.520 11.524 13.120 14.611 16.473 19.939 29.339 34.382 37.652 40.646 44.314 46.928 26 11.160 12.198 13.844 15.379 17.292 20.843 30.435 35.563 38.885 41.923 45.642 48.290 27 11.808 12.879 14.573 16.151 18.114 21.749 31.528 36.741 40.113 43.194 46.963 49.645 28 12.461 13.565 15.308 16.928 18.939 22.657 32.620 37.916 41.337 44.461 48.278 50.993 29 13.121 14.257 16.047 17.708 19.768 23.567 33.711 39.087 42.557 45.722 49.588 52.336 30 13.787 14.954 16.791 18.493 20.599 24.478 34.800 40.256 43.773 46.979 50.892 53.672Upper-Tail Areas Degrees of Freedom 0.25 0.10 0.05 0.025 0.01 0.005 1.0000 3.0777 6.3138 12.7062 31.8207 63.6574 0.8165 1.8856 2.9200 4.3027 6.9646 9.9248 0.7649 1.6377 2.3534 3.1824 4.5407 5.8409 0.7407 1.5332 2.1318 2.7764 3.7469 4.6041 0.7267 1.4759 2.0150 2.5706 3.3649 4.0322 0.7176 1.4398 1.9432 2.4469 3.1427 3.7074 0.7111 1.4149 1,8946 2.3646 2.9980 3.4995 0.7064 1.3968 1.8595 2.3060 2.8965 3.3554 0.7027 1.3830 1.8331 2.2622 2.8214 3.2498 0.6998 1.3722 1.8125 2.2281 2.7638 3.1693 0.6974 1.3634 1.7959 2.2010 2.7181 3.1058 0.6955 1.3562 1.7823 2.1788 2.6810 3.0545 0.6938 1.3502 1.7709 2.1604 2.6503 3.0123 14 0.6924 1.3450 1.7613 -2.1448 2.6245 2.9768 0.6912 1.3406 1.7531. 2.1315 2.6025 2.9467 16 0.6901 1.3368 1.7459 2.1199 2.5835 2.9208 17 0.6892 1.3334 1.7396 2.1098 2.5669 2.8982 18 0.6884 1.3304 1.7341 2.1009 2.5524 2.8784 19 0.6876 1.3277 1.7291 2.0930 2.5395 2.8609 20 0.6870 1.3253 1.7247 2.0860 2.5280 2.8453 21 0.6864 1.3232 1.7207 2.0796 2.5177 2.8314 22 0.6858 1.3212 1.7171 2.0739 2.5083 2.8188 23 0.6853 1.3195 1.7139 2.0687 2.4999 2.8073 24 0.6848 1.3178 1.7109 2.0639 2.4922 2.7969 0.6844 1.3163 1.7081 2.0595 2.4851 2.7874 26 0.6840 1.3150 1.7056 2.0555 2.4786 2.7787 27 0.6837 1.3137 1.7033 2.0518 2.4727 2.7707 28 0.6834 1.3125 1.7011 2.0484 2.4671 2.7633 29 0.6830 1.3114 1.6991 2.0452 2.4620 2.7564 30 0.6828 1.3104 1.6973 2.0423 2.4573 2.7500 31 0.6825 1.3095 1.6955 . 2.0395 2.4528 2.7740 32 0.6822 1.3086 1.6939 2.0369 2.4487 2.7385 33 0.6820 1.3077 1.6924 : 2.0345 2.4448 2.7333 34 0.6818 1.3070 1.6909 2.0322 2.4411 2.7284 35 0.6816 1.3062 1.6896 2.0301 2.4377 2.7238 36 0.6814 1.3055 1.6883 2.0281 2.4345 2.7195 37 0.6812 1.3049 1.6871 2.0262 2.4314 2.7154 38 0.6810 1:3042 1.6860 2.0244 2.4286 2.7116 39 0.6808 1.3036 1.6849 2.0227 2.4258 2.7079 40 0.6807 1.3031 1.6839 2.021 1 2.4233 2.7045 41 0.6805 1.3025 1.6829 2.0195 2.4208 2.7012 42. 0.6804 1.3020 1.6820 2.0181 2.4185 2.6981 43 0.6802 1.3016 1.6811 2.0167 2.4163 2.6951 44 0.6801 1.3011 1.6802 2.0154 2.4141 2.6923 45 0.6800 1.3006 1.6794 2.0141 2.4121 2.6896 46 0.6799 1.3022 1.6787 2.0129 2.4102 2.6870 47 0.6797 1.2998 1.6779 2.0117 2.4083 2.6846 48 0.6796 1.2994 1.6772 2.0106 2.4066 2.6822 continuedTable IV Standard Normal Distribution .01 -02 -03 05 .06 .07 .08 -34 0.0003 070003 070003 0.0003 0.0003 0.0003 0.0003 0.0003 0.0003 0.0002 -33 0.0005 0.0005 0.0005 0.0004 0.0004 0.0004 0.0004 0.0004 0.0004 0.0003 -3.2 0.0007 0.0007 0/0006 0.0006 0.0006 0.0006 0.0006 0/0005 070005 0.0005 -3.1 0.0010 0.0009 0.0009 0.0009 0.0008 0.0008 0.0008 0.0008 0.0007 0.0007 -3.0 0.0013 0.0013 0.0013 0.0012 0.0012 0.0011 0.0011 0.0011 0.0010 0.0010 -2.9 0.0019 0.0018 0,0018 0.0017 0.0016 0.0016 0.0015 0.0015 0.0014 0.0014 -2.8 0.0026 0.0025 0.0024 0.0023 0.0023 0.0022 0.0021 0,0021 0/0020 0.0019 -2.7 0.0035 0.0034 0/0033 0.0032 0.0031 0.0030 0.0029 0.0028 0.0027 0.0026 -2.6 0.0047 0.0045 0.0044 0.0043 0.0041 0.0040 0.0039 0.0038 0.0037 0.0036 -25 0.0062 0.0060 0.0059 0.0057 0.0055 0.0054 0.0052 0,0051 0.0049 0.0048 -2.4 0.0082 0/0080 0.0078 0.0075 0.0073 0.0071 0.0069 0.0068 0.0066 0.0064 -23 0.0107 0.0104 0.0102 0.0099 0.0096 0.0094 0.0091 0/0089 0.0087 0.0084 -2.2 0.0139 0.0136 0.0132 0.0129 0.0125 0.0122 0.0119 0.0116 0.0113 0.0110 -2.1 0.0179 0.0174 0.0170 0.0166 0.0162 0.0158 0.0154 0.0150 0.0146 0.0143 -2.0 0.0228 0.0222 0.0217 0.0212 0.0207 0.0202 0.0197 0.0192 0.0188 0.0183 -1.9 0.0287 0.0281 0.0274 0.0268 0.0262 0.0256 0.0250 0.0244 0.0239 0.0233 -1.8 0.0359 0.0351 0.0344 0.0336 0.0329 0.0322 0.0314 0.0307 0.0301 0.0294 -1.7 0.0446 0.0436 0.0427 0.0418 0.0409 0.0401 0.0392 0.0384 0.0375 0.0367 -1.6 0.0548 0.0537 0.0526 0.0516 0.0505 0.0495 0.0485 0.0475 0.0465 0.0455 -15 0.0668 0 0655 0.0643 0.0630 0.0618 0.0606 0.0594 0.0582 0.0571 0.0559 -14 0.0808 0.0793 0.0778 0.0764 0.0749 0.0735 0.0721 0.0708 0.0694 0.0681 -13 0.0968 0.0951 0.0934 0.0918 0.0901 0.0885 0.0869 0.0853 0.0838 0.0823 -1.2 0.1151 0.1131 0.1112 0.1093 0.1075 0.1056 0.1038 0.1020 0.1003 0.0985 -1.1 0.1357 0.1335 0.1314 0.1292 0.1271 0.1251 0.1230 0.1210 0.1190 0.1170 -1.0 0.1587 0.1562 0.1539 0.1515 0.1492 0.1469 0.1446 0.1423 0.1401 0.1379 -0.9 0.1841 0.1814 0.1788 0.1762 0.1736 0.1711 0.1685 0.1660 0.1635 0.1611 -08 0.2119 0.2090 0.2061 0.2033 0.2005 0.1977 0.1949 0.1922 0.1894 0.1867 -0.7 0.2420 0.2389 0.2358 0.2327 0.2296 0.2266 0.2236 0.2206 0.2177 0.2148 -0.6 0.2743 0.2709 0.2676 0.2643 0.2611 0.2578 0.2546 0.2514 0.2483 0.2451 -05 0.3085 0.3050 03015 0.2981 0.2946 0.2912 0.2877 0.2843 0.2810 0.2776 -04 0.3446 03409 03372 0.3336 0.3300 0.3264 0.3228 0.3192 0.3156 0.3121 -03 0.3821 03783 0.3745 0.3707 0.3669 0.3632 0.3594 0.3557 0.3520 0.3483 -0.2 0.4207 0.4168 0.4129 0.4090 0.4052 0.4013 0.3974 0.3936 0.3897 0.3859 -0.1 0.4602 0.4562 0.4522 0.4483 0.4443 0.4404 0.4364 0.4325 0.4286 0.4247 -0.0 0.5000 0.4960 0.4920 0.4880 0.4840 0.4801 0.4761 0.4721 0.4681 0.4641STANDARD NORMAL DISTRIBUTION: Table Values Represent AREA to the LEFT of the Z score. Z -00 .01 02 .03 .05 ,06 07 08 .09 0.0 50000 50399 50798 51197 51595 51994 52392 52790 53188 53586 0,1 53983 54380 54776 $5172 $5567 $5962 56356 56749 57142 .57535 0.2 .57926 .58317 58706 59095 59483 59871 .60257 .60642 .61026 .61409 .61791 62172 62552 62930 63307 63683 64058 64431 .64803 65173 0.4 .65542 65910 66276 66610 67003 67364 67724 68082 68439 68793 0.5 .69146 69497 69847 .70194 70540 70884 .71226 .71566 71904 72240 0.6 .72575 .72907 .73237 .73565 .73891 -74215 .74537 .74857 .75175 .75490 0.7 .75804 .76115 .76424 .76730 .77035 .77337 .77637 .77935 .78230 .78524 0.8 .78814 .79103 .79389 .79673 .79955 80234 80511 80785 .81057 .81327 0.9 .81594 .81859 .82121 82381 82639 82894 .83147 .83398 .83646 16868 1.0 .84134 .84375 84614 84849 85083 .85314 .85543 .85769 85993 86214 1.1 .86433 .86650 .86864 87076 87286 .87493 .87698 .87900 .88100 .88298 1.2 .88493 ,88686 ,88877 89065 89251 89435 89617 89796 .89973 .90147 1.3 90320 .90490 .90658 90824 90988 91149 .91309 .91466 .91621 .91774 1.4 .91924 92073 .92220 92364 92507 92647 92785 92922 93056 93189 1.5 .93319 .93448 .93574 93699 93822 93943 .94062 .94179 .94295 .94408 1.6 94520 .94630 94738 94845 94950 95053 .95154 95254 .95352 .95449 1.7 .95543 .95637 .95728 95818 95907 95994 96080 96164 .96246 .96327 1.8 .96407 .96-485 .96562 -96638 -96712 -96784 .96856 96926 .96995 .97062 1.9 97128 97193 97257 97320 97381 97441 97500 97558 97615 97670 2.0 97725 97778 .97831 -97882 .97932 -97982 98030 98077 .98124 .98169 2.1 98214 98257 .98300 98341 98382 98422 98461 .98500 98537 .98574 2.2 .98610 98645 .98679 98713 98745 98778 98809 98840 98870 .98899 2.3 .98928 98956 .98983 99010 99036 99061 99086 99111 .99134 .99158 2.4 99180 99202 99224 99245 99265 99286 99305 99324 99343 99361 2.5 99379 99396 99413 99430 -99446 99461 99477 99492 99506 99520 2.6 .99534 99547 .99560 99573 99585 99598 99609 99621 99632 99643 2.7 99653 99664 .99674 99683 99693 .99702 .99711 .99720 .99728 .99736 2.8 .99744 .99752 99760 99767 99774 99781 99788 99795 99801 99807 2.9 99813 .99819 99825 99831 99836 99841 99846 99851 99856 99861 3.0 99865 99869 .99874 99878 99882 99886 99889 99893 99896 99900 3.1 .99903 .99906 .99910 99913 -99916 .99918 .99921 99924 .99926 .99929 3.2 .99931 .99934 99936 99938 .99940 99942 99944 99946 99948 99950 3.3 .99952 .99953 .99955 99957 99958 99960 99961 99962 99964 99965 3.4 99966 99968 99969 99970 99971 99972 99973 99974 99975 99976 3.5 99977 99978 99978 99979 99980 99981 99981 99982 99983 99983 3.6 .99984 .99985 .99985 99986 99986 99987 99987 99988 .99988 .99989 3.7 99989 99990 .99990 99990 99991 99991 99992 99992 99992 .99992 3.8 .99993 .99993 .99993 .99994 99994 99994 99994 .99995 .99995 .99995 3.9 .99995 .99995 99996 99996 99996 99996 99996 99996 .99997 99997