1. Given the attached t-table what are the t-values required for a variable to be significant at the p 0.01 and p 0.05 and 0.10 levels if the degrees of freedom are 3,5,10,16,23,30,60 and infinity.
   

694 APPENDIXES TABLE C-2 |Areas in the Tails of ther -t Probabilities Degree 20 .01 of -10 05 102 60 140 Freedom BO 1.376 43.078 6.314 12.706 31.821 63.657 0.727 4.303 6.965 3 9.925 2 D.289 1.061 1.886 0.978 1.638 2.353 3.182 4.541 5.841 0.277 0.569 2.132 0.271 0.941 2.776 3.747 4.604 1.476 2.015 3.365 0.920 4.032 1.943 2.447 3.143 3.707 6 0.265 0.553 0.906 1.440 1.415 1,895 0.263 0.896 2.365 2.998 3.499 0,262 0.546 0.889 1,397 1.860 2.306 2.896 3.355 0.883 1.383 1.833 2.262 2.821 3.250 9 0.261 0.543 0.875 1.372 1.812 2.228 2.764 3.169 10 11 D.260 0.540 0,876 - 1,363 2.201 2718 3.106 0.539 0.873 1.356 2,179 2.681 3.055 13 0.259 0.538 0.870 1.771 2.160 2.650 3.012 0.258 0,868 1.761 ONE: 2.145 2.624 15 0,258 0.536 0.856 1341 1.753 2.131 2.602 2.947 16 J.258 0.535 0 865 1,337 1.746 2.120 2.583 2.921 17 0.257 0.534 0,863 1.333 1.740 2.110 2.567 2.898 18 D.257 0.534 0.862 1.330 1.734 2.101 2.552 2.878 19 0.257 0.533 0.261 1.328 1.725 2.093 2.539 2.861 20 0.257 0.533 0.860 1 325 1.725 2.086 2.529 2.845 21 0.257 0.532 0.859 2.518 2.831 0.256 0.532 0.858 1:321 1.721 1.717 2.080 23 0.256 0.532 -0.858 2.074 2.508 1319 2.819 :0.256- 0.531 0.857 2.069 . 230.256 1,318 2.500 2807 0.531 1711 2.064 2.492 2.797 26 0.256 0.531 0.856 1315 1.708 0.856 2.060 27 0.256 0.531 1.706 2.056 2.485 2.787 0.855 2.479 1.314 1.703 2.779 28 0.256 0.530 0.855 29 0.256 1.313 2.052 2:473 2:771 0.530 1.701 0.854 2.048 2.467 2:763 30 0.256 0.530 1,311 1.699 0.854 2.045 2.462 2,756 40 0.255 0.529 0.851 1.697 2.042 2.457 2.750 60 120 0.254 1303 1.684 2.021 2.423 2.704 0.254 0.526 0.848 1.296 2.000 0.253 1.289 1.671 2.390 0.524 0.845 0.842 1.658 2.660 1282 1.645 1.980 2358 1.960 2.617 2.326 2.576 Note: The probabilities given in the table are for two-tailed tests. Thus, a probability of 0.05 allows for 0.025 in each tail. For example, for the probability of 0,05 and 21 df, 1= 2.080. This means that 2.5 percent of the area under the I distribution lies to the right of ? = 2.080, and 2.5 percent to the left of / = 2,080. Source: From table III of Fisher and Yates, Statistical Tables for Biological, Agricultural and Medical Research, 6th ed., 1974, published by Longman Group Led., London (previously by Oliver & Boyd, Edinburgh), by permission of the authors and publishers