Page 1: Question 8 (5 points) 1 2 Listen -- Tables Page 2: Researchers want to study noise levels produced by vehicles on a busy street. The 3 mean noise level for 35 vehicles was 85.6 decibels, and population standard 4 deviation 4.5 decibels. - - Page 3: a) What distribution should be used, z or t? Type z or t in the answer box. [1 mark] 5 6 b) Find the critical Value for the 78% confidence interval. Write exact value from the table. [2 marks] Page 4: c) Find margin of error rounded to two decimal places. For example, 2.22 [1 mark] 8 d) Find the 78% confidence interval of the true mean. Round answers to two Page 5: decimal places and separate the lower and upper limits of the interval with a comma and no space. For example: 10.13, 12.64 [1 mark] 10 A/ Previous Page Next Page Page 4 of 5 OLD - CENAC ENG US55% . . . e.centennialcollege.ca 1:54 PM Fri Apr 15 POSITIVE z Scores .09 Table A-2 (continued) Cumulative Area from the LEFT .08 .05 .06 .07 4 AppA 04 .5359 .02 .03 .5239 .5279 .5319 5199 Z .00 .01 .5160 .5753 .5040 5080 5120 .5714 .5596 .5636 .5675 6103 6141 0.0 5000 5557 .5398 .5438 .5478 .5517 6026 .6064 5948 5987 6443 6480 .6517 0.1 5910 .5793 5832 5871 .6368 6406 .629 .6331 6808 6844 6879 0.2 6217 6255 6772 6179 6664 .6700 6736 .7190 .7224 0.3 .7157 6554 6591 .6628 .7123 7019 7054 7088 7549 0.4 7454 7486 7517 6950 6985 7422 .7823 .7852 0.5 6915 .7291 7324 .7357 7389 .7764 .7794 .770 7734 8133 0.6 7257 7673 8051 8078 8106 7611 7642 802 7580 7967 7995 8340 .8365 .8389 0.7 7910 7939 7881 .8264 .8289 .8315 3599 3621 0.8 8186 .8212 .8238 3577 8159 8508 8531 8554 8830 0.9 8461 .8485 8810 .8749 .8770 8790 9015 1.0 8413 8438 8686 .8708 .8729 8997 8665 8944 8962 8980 8643 .8925 9147 9162 .9177 1.1 8888 .8907 .9131 8849 8869 .908 .9099 .9115 9292 9306 9319 1.2 9049 .9066 9279 .9441 1.3 9032 9236 9251 9265 9406 9418 .9429 9207 9222 9394 9545 1.4 9192 .9370 9382 9535 .9345 9357 .9505 9515 9525 9495 962 9633 1.5 9332 9474 9484 .959 9608 9616 9706 1.6 9452 9463 .9582 .959 .9699 .956 9573 9678 .9686 9693 9554 9671 .9767 1.7 9664 9756 9761 9641 9649 9656 9744 9750 9738 9812 3817 1.8 9808 9719 9726 9732 .9803 9713 .9793 .9798 9854 .9857 1.9 778 9783 9788 9834 9838 .9842 .9846 .9850 9887 9890 2.0 .977 9830 .9878 988 9884 .9916 2.1 9821 9826 .986 9871 .9875 .9909 9911 .9913 3864 .9906 9934 9936 9861 2.2 9904 9932 9896 9898 9901 9893 .9929 .9931 9952 2.3 .9922 .992 9927 ,9951 9918 .9920 9945 .9946 9948 9949 9943 9962 9963 9964 2.4 9938 9940 9941 .995 .9960 9961 9957 9972 .9973 .9974 2.5 9953 9955 9956 .9969 .997 9971 .9980 9981 2.6 9967 .996 9979 9979 .996 9977 9978 .9986 9986 2.7 9965 9975 9976 9977 9985 9984 9984 9985 9990 2.8 9974 9982 .9983 9989 9989 9990 .9982 9989 9993 .9993 2.9 3981 9988 9988 9987 .9992 .9992 9992 9987 9995 3.0 9987 9991 .999 .9992 .9995 9995 9990 9991 9994 .9994 .9994 .9996 .9997 3.1 9994 9993 9993 9994 .9996 .9996 3.2 .9996 .9996 .9996 9997 9998 9995 9997 .9997 3.3 995 9995 9997 .9997 .9997 9997 9997 3.4 9997 Common Critical Values 3.50 and up 9999 Confidence Critical Value NOTE: For values of z above 3.49, use 0.9999 for the area. Level " Use these common values that result from interpolation: 0.90 1.645 0.95 1.96 z score Area 0.99 2.575 1.645 0.9500 2.575 0.995055% . . . C 1:54 PM Fri Apr 15 e.centennialcollege.ca Done NEGATIVE z Scores 0 Table A-2 Standard Normal (z) Distribution: Cumulative Area from the LEFT 501# AppA.02 2 09 .06 07 03 04 05 .00 .01 02 .0002 -3.50 and .0003 0001 .0003 .0003 .0003 .0003 lower .0003 .0004 .0003 0003 .0003 .0004 .0004 -3.4 .0003 .0004 .0005 0004 .0004 0006 0005 0005 0005 -3.3 .0005 .0005 .000 .000 0007 0007 .000 .000 0008 .0007 2007 0008 .0008 -3.2 0009 .0008 0009 0011 0010 0010 0009 0011 -3.1 0010 0012 0011 0014 0013 0013 0012 0014 -3.0 0013 .0016 .0016 .0015 .0015 0019 .0018 .0018 0017 2019 0022 0021 0021 0020 -2.9 0023 0023 .0025 .0029 .0028 .0027 .0026 0024 -2.8 2026 .0031 0030 .0032 0037 .0036 0035 0034 0033 .0039 .0038 -2.7 .0041 .0040 .0048 0045 0044 .0043 .0051 0049 .0052 -2.6 0047 0057 .005 .0054 9900 0064 0062 .006 1059 0068 - 2.5 0073 0071 0069 0084 0078 0075 .0089 .0087 -2.4 0082 0080 0094 .0091 0099 0096 0113 0110 0104 0102 0116 -2.3 0107 .0122 0119 .0125 .0143 .0136 .0132 0129 0154 .0150 .0146 -2.2 0139 .0166 .0162 .0158 .0170 0192 0188 0183 0174 0197 -2.1 .0179 0207 0202 .0217 0212 .0239 .0233 0222 0256 0250 0244 -2.0 0228 0268 .0262 0294 274 0307 0301 -1.9 0287 0281 0314 1344 .0329 .032 .0336 0384 0375 .0367 0359 0351 .0392 -18 0418 .0409 .0401 0455 .0427 0446 0436 0485 0475 0465 -1.7 0516 .0505 .0495 .0537 0526 .0594 0582 .0571 .0559 -1.6 0548 .0630 0618 .0606 0681 .0643 0708 0694 -1.5 0668 .0655 0749 0735 0721 0764 .0838 .0823 0808 0793 0778 .0869 .0853 -1.4 0918 .0901 .0885 1003 0985 .0951 0934 1056 1038 1020 -1.3 0968 1093 .1075 .1190 .1170 .1112 .1210 -1.2 1151 1131 1271 .1251 .1230 1379 1335 .1314 1292 .1446 .1423 1401 -1.1 1357 1469 1515 1492 .1635 1611 1562 1539 1685 1660 -1.0 1587 .176 .1736 1711 .1922 .1894 1867 1814 1788 1949 0.9 1841 2033 2005 .1977 .2177 .2148 .2090 2061 2236 2206 -0.8 2119 2327 .2296 2266 2358 2514 .2483 2451 -0.7 ,2420 2389 2578 .2546 2810 2776 2709 2676 .2643 2611 2912 2877 2843 -0.6 2743 2981 .2946 .3192 .3156 .3121 -0.5 3085 3050 3015 .3300 .3264 .3228 .3336 .3483 3409 .3372 .3557 .3520 .359 0.4 3446 3707 3669 .3632 .3897 .3859 3821 .3783 3745 0.3 4013 3974 3936 4129 4090 4052 4364 4325 .4286 4247 4207 4168 0.2 4522 4483 4443 4404 4641 4602 4562 4761 4721 4681 0.1 4801 492 4880 4840 0.0 5000 496 NOTE: For values of z below -3.49, use 0.0001 for the area .Use these common values that result from interpolation: z score Area -1.645 0.0500 -2.575 0.00501:57 PM Fri Apr 15 . . . 54% e.centennialcollege.ca Q T V 7 (1 of1 ) - + Automatic Zoom > > Table F The t Distribution Confidence intervals 80% 90% 95% 98% 99% One tail, a 0.10 0.05 0.025 0.01 0.005 d.f. Two tails, a 0.20 0.10 0.05 0.02 0.01 3.078 6.314 2.70 31.82 3.657 1.886 2.920 4.303 6.965 9.925 1.638 2.353 3.182 4.54 5.841 1.533 2.132 2.776 3.747 4.604 JaUAWN 1.476 2.015 2.571 3.365 4.032 1.440 1.943 2.447 3.143 3.707 1.415 1.895 2.365 2.998 3.490 0 00 N 1.397 1.860 2.306 2.896 3.355 1.383 1.833 2.262 2.821 3.250 10 1.372 1.812 2.228 2.764 3.169 11 1.363 1.796 2.201 2.718 3.106 1.356 1.782 2.179 2.681 3.055 1.350 1.771 2.160 2.650 3.012 1.345 1.761 2.145 2.624 2.977 1.341 1.753 2.131 2.602 2.947 1.337 1.746 2. 120 2.583 2.921 1.333 1.740 2.110 2.567 2.898 1.330 1.734 2. 101 2.552 2.878 1.328 1.729 2.093 2.861 1.325 1.725 2.086 2.528 2.845 1.323 1.721 2.080 2.518 2.831 1.321 1.717 2.074 2.508 2.819 1.319 1.714 2.069 2.500 2.807 1.318 1.711 2.064 2.492 2.797 1.316 1.708 2.060 2.485 2.787 1.315 1.706 2.056 2.479 2.779 1.314 1.703 2.052 2.473 2.771 1.313 1.701 2.048 2.467 2.763 1.311 1.699 2.045 2.462 2.756 1.310 1.697 2.042 2.457 2.750 1.309 1.694 2.037 2.449 2.738 1.307 1.691 2.032 2.441 2.728 1.306 1.688 2.028 2.434 2.719 1.304 1.686 2.024 2.429 2.712 40 1.303 1.684 2.021 2.423 2.704 45 1.301 1.679 2.014 2.412 2.690 50 1.299 1.676 2.009 2.403 2.678 55 1.297 1.673 2.004 2.396 2.668 60 1.296 1.671 2.000 2.390 2.660 65 1.295 1.669 1.997 2.385 2.654 70 1.294 1.667 1.994 2.381 2.648 75 1.293 1.665 1.992 2.377 2.643 80 1.292 1.664 1.990 2.374 2.639 90 1.291 1.662 1.987 2.368 2.632 100 1.290 1.660 1.984 2.364 2.626 500 1.283 1.648 1.965 2.334 2.586 1000 1.282 1.646 1.962 2.330 2.581 2) 00 1.282 .645% 1.960 2.326' 2.576d "This value has been rounded to 1.28 in the textbook. One tail Two tails "This value has been rounded to 1.65 in the textbook. "This value has been rounded to 2.33 in the textbook. Area Area - Area "This value has been rounded to 2.58 in the textbook. 2 Source: Adapted from W. H. Beyer, Handbook of Tables for Probability and Statistics, 2nd ed., CRC Press, Boca Raton, Fla., 1986. Reprinted with permission