Areas under the Normal Curve 00 .01 .02 .03 .04 .05 .06 07 08 .09 -3.4 0.0003 0.0003 0.0003 0.0003 0.0003 0.0003 0.0003 0.0003 0.0003 0.0002 -3.4 -3.3 0.0005 0.0005 0.0005 0.0004 0.0004 0.0004 0.0004 0.0004 0.0004 0.0003 -3.3 -3,2 0.0007 0.0007 0.0006 0.0006 0.0006 0.0006 0.0006 0.0005 0.0005 0.0005 -3.2 -3.1 0.0010 0.0009 0.0009 0.0009 0.0008 0.0008 0.0008 0.0008 0.0007 0.0007 -3.1 -3.0 0.0013 0.0013 0.0013 0.0012 0.0012 0.0011 0.0011 0.0011 0.0010 0.0010 -3.0 -2.9 0.0019 0.0018 0.0018 0.0017 0.0016 0.0016 0.0015 0.0015 0.0014 0.0014 -2.9 -2.8 0.0026 0.0025 0.0024 0.0023 0.0023 0.0022 0.0021 0.0021 0.0020 0.0019 -2.8 -2.7 0.0035 0.0034 0.0033 0.0032 0.0031 0.0030 0.0029 0.0028 0.0027 0.0026 -2.7 -2.6 0.0047 0.0045 0.0044 0.0043 0.0041 0.0040 0.0039 0.0038 0.0037 0.0036 -2.6 -2.5 0.0062 0.0060 0.0059 0.0057 0.0055 0.0054 0.0052 0.0051 0.0049 0.00-48 -2.5 -2.4 0.0082 0.0080 0.0078 0.0075 0.0073 0.0071 0.0069 0.0068 0.0066 0.0064 -2.4 -2.3 0.0107 0.0104 0.0102 0.0099 0.0096 0.0094 0.0091 0.0089 0.0087 0.0084 -2.3 -2.2 0.0139 0.0136 0.0132 0.0129 0.0125 0.0122 0.0119 0.0116 0.0113 0.0110 -2.2 -2.1 0.0179 0.0174 0.0170 0.0166 0.0162 0.0158 0.0154 0.0150 0.0146 0.0143 -2.1 -2.0 0.0228 0.0222 0.0217 0.0212 0.0207 0.0202 0.0197 0.0192 0.0188 0.0183 -2.0 -1.9 0.0287 0.0281 0.0274 0.0268 0.0262 0.0256 0.0250 0.0244 0.0239 0.0233 -1.9 -1.8 0.0359 0.0351 0.0344 0.0336 0.0329 0.0322 0.0314 0.0307 0.0301 0.0294 -1.8 -1.7 0.0446 0.0436 0.0427 0.0418 0.0409 0.0401 0.0392 0.0384 0.0375 0.0367 -1.7 -1.6 0.0548 0.0537 0.0526 0.0516 0.0505 0.0495 0.0485 0.0475 0.0465 0.0455 -1.6 -1.5 0.06G8 0.0655 0.0643 0.0630 0.0618 0.060G 0.0594 0.0582 0.0571 0.0559 -1.5 -1.4 0.0808 0.0793 0.0778 0.0764 0.0749 0.0735 0.0721 0.0708 0.0694 0.0681 -1.4 -1.3 0.0968 0.0951 0.0934 0.0918 0.0901 0.0885 0.0869 0.0853 0.0838 0.0823 -1.3 -1.2 0.1151 0.1131 0.1112 0.1093 0.1075 0.1056 0.1038 0.1020 0.1003 0.0985 -1.2 -1.1 0.1357 0.1335 0.1314 0.1292 0.1271 0.1251 0.1230 0.1210 0.1190 0.1170 -1.1 -1.0 0.1587 0.1562 0.1539 0.1515 0.1492 0.1469 0.1446 0.1423 0.1401 0.1379 -1.0 -0.9 0.1841 0.1814 0.1788 0.1762 0.1736 0.1711 0.1685 0.1660 0.1635 0.1611 -0.9 -0.8 0.2119 0.2090 0.2061 0.2033 0.2005 0.1977 0.1949 0.1922 0.1894 0.1867 -0.8 -0.7 0.2420 0.2389 0.2358 0.2327 0.2296 0.2266 0.2236 0.2206 0.2177 0.2148 -0.7 -0.6 0.2743 0.2709 0.2676 0.2643 0.2611 0.2578 0.2546 0.2514 0.2483 0.2451 -0.6 -0.5 0.3085 0.3050 0.3015 0.2981 0.2946 0.2912 0.2877 0.2843 0.2810 0.2776 -0.5 -0.4 0.3446 0.3409 0.3372 0.3336 0.3300 0.3264 0.3228 0.3192 0.3156 0.3121 -0.4 -0.3 0.3821 0.3783 0.3745 0.3707 0.3669 0.3632 0.3594 0.3557 0.3520 0.3483 -0.3 -0.2 0.4207 0.4168 0.4129 0.4090 0.4052 0.4013 0.3974 0.3936 0.3897 0.3859 -0.2 -0.1 0.4602 0.4562 0.4522 0.4483 0.4443 0.4404 0.4364 0.4325 0.4286 0.4247 -0.1 -0.0 0.5000 0.4960 0.4920 0.4880 0.4840 0.4801 0.4761 0.4721 0.4681 0.4641 -0.0 .00 .01 .02 03 .04 05 06 07 .08 .09Areas under the Normal Curve .00 .01 02 .03 .04 .05 .06 07 08 .09 0.0 0.5000 0.5040 0.5080 0.5120 0.5160 0.5199 0.5239 0.5279 0.5319 0.5359 0.0 0.1 0.5398 0.5438 0.5478 0.5517 0.5557 0.5596 0.5636 0.5675 0.5714 0.5753 0.1 0.2 0.5793 0.5832 0.5871 0.5910 0.5948 0.5987 0.6026 0.6064 0.6103 0.6141 0.2 0.3 0.6179 0.6217 0.6255 0.6293 0.6331 0.6368 0.6406 0.6443 0.6480 0.6517 0.3 0.4 0.6554 0.6591 0.6628 0.6664 0.6700 0.6736 0.6772 0.6808 0.6844 0.6879 0.4 0.5 0.6915 0.6950 0.6985 0.7019 0.7054 0.7088 0.7123 0.7157 0.7190 0.7224 0.5 0.6 0.7257 0.7291 0.7324 0.7357 0.7389 0.7422 0.7454 0.7486 0.7517 0.7549 0.6 0.7 0.7580 0.7611 0.7642 0.7673 0.7704 0.7734 0.7764 0.7794 0.7823 0.7852 0.7 0.8 0.7881 0.7910 0.7939 0.7967 0.7995 0.8023 0.8051 0.8078 0.8106 0.8133 0.8 0.9 0.8159 0.8186 0.8212 0.8238 0.8264 0.8289 0.8315 0.8340 0.8365 0.8389 0.9 1.0 0.8413 0.8438 0.8461 0.8485 0.8508 0.8531 0.8554 0.8577 0.8599 0.8621 1.0 1.1 0.8643 0.8665 0.8686 0.8708 0.8729 0.8749 0.8770 0.8790 0.8810 0.8830 1.1 1.2 0.8849 0.8869 0.8888 0.8907 0.8925 0.8944 0.8962 0.8980 0.8997 0.9015 1.2 1.3 0.9032 0.9049 0.906G 0.9082 0.9099 0.9115 0.9131 0.9147 0.9162 0.9177 1.3 0.9192 0.9207 0.9222 0.9236 0.9251 0.9265 0.9279 0.9292 0.9306 0.9319 1.4 1.5 0.9332 0.9345 0.9357 0.9370 0.9382 0.9394 0.9406 0.9418 0.9429 0.9441 1.5 1.6 0.9452 0.9463 0.9474 0.9484 0.9495 0.9505 0.9515 0.9525 0.9535 0.9545 1.6 1.7 0.9554 0.9564 0.9573 0.9582 0.9591 0.9599 0.9608 0.9616 0.9625 0.9633 1.7 1.8 0.9641 0.9649 0.9656 0.9664 0.9671 0.9678 0.9686 0.9693 0.9699 0.9706 1.8 1.9 0.9713 0.9719 0.9726 0.9732 0.9738 0.9744 0.9750 0.9756 0.9761 0.9767 1.9 2.0 0.9772 0.9778 0.9783 0.9788 0,9793 0.9798 0.9803 0,9808 0.9812 0.9817 2.0 2.1 0.9821 0.9826 0.9830 0.9834 0.9838 0.9842 0.9846 0.9850 0.9854 0.9857 2.1 2.2 0.9861 0.9864 0.9868 0.9871 0.9875 0.9878 0.9881 0.9884 0.9887 0.9890 2.2 2.3 0.9893 0.9896 0.9898 0.9901 0.9904 0.9906 0.9909 0.9911 0.9913 0.9916 2.3 2.4 0.9918 0.9920 0.9922 0.9925 0.9927 0.9929 0.9931 0.9932 0.9934 0.9936 2.4 2.5 0.9938 0.9940 0.9941 0.9943 0.9945 0.9946 0.9948 0.9949 0.9951 0.9952 2.5 2.6 0.9953 0.9955 0.9956 0.9957 0.9959 0.9960 0.9961 0.9962 0.9963 0.9964 2.6 2.7 0.9965 0.9966 0.9967 0.9968 0.9969 0.9970 0.9971 0.9972 0.9973 0.9974 2.7 2.8 0.9974 0.9975 0.9976 0.9977 0.9977 0.9978 0.9979 0.9979 0.9980 0.9981 2.8 2.9 0.9981 0.0982 0.9982 0.9983 0.9984 0.9984 0.9985 0.9985 0.9986 0.9986 2.9 3.0 0.9987 0.9987 0.9987 0.9988 0.9988 0.9989 0.9989 0.9989 0.9990 0.9990 3.0 3.1 0.9990 0.9991 0.9991 0.9091 0.9992 0.9992 0.9992 0.9092 0.9093 0.9993 3.1 3.2 0.9993 0.9993 0.9994 0.9994 0.9994 0.9994 0.9994 0.9995 0.9995 0.9995 3.2 3.3 0.9995 0.9995 0.9995 0.9996 0.9996 0.9996 0.9996 0.9996 0.9996 0.9997 3.3 3.4 0.9997 0.9997 0.9997 0.9997 0.9997 0.9997 0.9997 0.9997 0.9997 0.9998 3.4 .00 .01 .02 03 .04 .05 .06 .07 08 109Critical Values of the ?-Distribution 0.40 0.30 0.20 0.15 0.10 0.05 0.025 0.325 0.727 1.376 1.963 3.078 6.314 12.706 0.289 0.617 1.061 1.386 1.886 2.920 4.303 0.277 0.584 0.978 1.250 1.638 2.353 3.182 0.271 0.569 0.941 1.190 1.533 2.132 2.776 0.267 0.559 0.920 1.156 1.476 2.015 2.571 0.265 0,553 0.906 1.134 1.440 1.943 2.447 0.263 0.549 0.896 1.119 1.415 1.895 2.365 0.262 0.546 0.889 1.108 1.397 1.860 2.306 9 0.261 0.543 0.883 1.100 1.383 1.833 2.262 10 0.260 0.542 0.879 1.093 1.372 1.812 2.228 11 0.260 0.540 0.876 1.088 1.363 1.796 2.201 12 0.259 0.539 0.873 1.083 1.356 1.782 2.179 13 0.259 0.538 0.870 1.079 1.350 1.771 2.160 14 0.258 0.537 0.868 1.076 1.345 1.761 2.145 15 0.258 0.536 0.866 1.074 1.341 1.753 2.131 16 0.258 0.535 0.865 1.071 1.337 1.746 2.120 17 0.257 0.534 0.863 1.069 1.333 1.740 2.110 18 0.257 0.534 0.862 1.067 1.330 1.734 2. 101 19 0.257 0.533 0.861 1.066 1.328 1,729 2.093 20 0.257 0.533 0.860 1.064 1.325 1.725 2.086 21 0.257 0.532 0.859 1.063 1.323 1.721 2.080 22 0.256 0.532 0.858 1.061 1.321 1.717 2.074 23 0.256 0.532 0.858 1.060 1.319 1,714 2.069 24 0.256 0.531 0.857 1.059 1.318 1.711 2.064 25 0.256 0.531 0.856 1.058 1.316 1.708 2.060 20 0.256 0,531 0.856 1.058 1.315 1.706 2.056 27 0.256 0.531 0.855 1.057 1.314 1.703 2.052 28 0.256 0.530 0.855 1.056 1.313 1.701 2.048 29 0.256 0.530 0.854 1.055 1.311 1.699 2.045 30 0.256 0,530 0.854 1.055 1.310 1.697 2.042 40 0.255 0.529 0.851 1.050 1.303 1.684 2.021 60 0.254 0.527 0.848 1.045 1.296 1.671 2.000 120 0.254 0.526 0.845 1.041 1.289 1.658 1.980 0.253 0.524 0.842 1.036 1.282 1.645 1.960 0.40 0.30 0.20 0.15 0.10 0.05 0.025Critical Values of tho r-Distn'butirm a 0.02 0.015 0.01 0.0015 0.005 0.1325 0.0M5 I? 1 15.894 21.315 81.821 42.433 83.666 127.32! 836.578 2 4.849 5.010 0.900 3.078 2W5 14.089 31.6\"] 3 3.482 3.396 4.541 5.047 5.841 7.458 12.024 :4 2.009 5.298 3.747 4..\" 4311 5.598 8.610 11 2.757 mm 3.346 3.634 4.- 4.772 cm 8 2 .012 m 8.143 3.872 3.707 4.317 5.250 7 2.517 2.715 2.998 3.\" 3.499 4.029 was 8 2.440 2.34 2.800 3.35 3.355 3.333 5.041 O 2.308 2.574 2821 2.909 2.250 3.6\"! 4.731 10 2.250 2.527 2.744 2m 3.160 3.581 4.587 11 2.323 2.401 2.718 2.379 3.113 3.407 4.437 12 2.303 2.401 2.001 an: 3.05% 8.428 4.318 12 2.282 2.4.3 2850 2.001 3.012 3372 4.221 14 2.204 2.415 2.824 2.771 2.977 3.338 4.143 15 2.249 m 2.502 2.745 2.947 3.2% 4.073 18 2.225 2.282 2.533 2.724 2.021 3.252 4.015 1'? 2.224 m 2.567 2.713 2.999 3222 3-965 18 2.214 2.3230 2.552 2.959 2378 3.197 3.922 1. 2.235 2.340 2.539 2.874 2.861 3.174 3.883 M 2-197 2330 2523 2-001 2.845 3153 3350 21 2.189 2.828 2.518 2.849 2.831 8.185 8.819 22 2.183 2.320 2.008 2.339 2.819 2119 3.792 20 2.177 2.313 2.500 2.029 2.\" 3.104 3.738 24 2.172. 2.307 2.402 2.9m 2.707 3.091 3.745 25 2.107 2.30! 2.485 2.612 2.787 1078 3.7% 28 2.102 use 2.470 2.008 2.770 3.137 3.707 21' 2.158 2.201 2.472 2.508 2.771 3.067 3.6% 23 2 .154 2.230 2.457 2.502 2.7\" 3.047 8.074 20 2.150 2.232 2.462 2.5\" 2.750 3.088 3.000 31 2.147 2.279 2.457 2.531 2.751 3.090 3.646 I] 2.121 2.50 2.423 mm 2.704 2.971 2.551 HI 2.\" 1.2.300 2.504 2.\") 2.915 3.480 I\" 2.070 2.13 2.858 2.\" 2.617 2m $473 an 2.154 2.170 2.128 9.439 2.676 23.17 9.290 C 0.02 0.015 0.01 0.0075 0.\" 0.1325 moons A random sample of 13 shearing pins is taken in a study of the Rockwell hardness of the pin head. Measurements on the Rockwell hardness are made for each of the 13, yielding an average value of 48.50 with a sample standard deviation of 1.8. Assuming the measurements to be normally distributed, construct a 90% condence interval for the mean Rockwell hardness. Click here to view page 1 of the standard normal distribution table. Click here to view p_age 2 of the standard normal distribution table. Click here to view page 1 of the table of critical values of the t-distribution. Click here to view page 2 of the table of critical values of the t-distribution. The condence interval is D