260 



INDEX 



Degrees of freedom (D/F), for estimate 

 of standard deviation of X, 162 



for estimate of variance about trend 

 line, 210 



for t-test, 163, 178, 211, 218 

 Deviations from the mean, 14 

 Dice, classes of events, 52 

 Difference between two means, 176, 179 

 Distribution, binomial frequency, graph, 

 78 



cumulative, 23, 25 



normal frequency, curve, 91, 93 



normal frequency, formula, 90, 92 



normal probability, curve, 96 



normal probability, table, 249 



of chi-square, 133, 252 



of correlation, r, 218 



of difference between means, X\ — x<i, 

 176 



of mean, x, 155, 157, 158 



of t, 162, 251 



of z = (1/2) log.[(l + r)/(l - r)], 219 



standard normal, 92, 249 

 Dixon, Wilfrid J., 48, 112, 152, 191, 242 

 Dot (Scatter) diagram, 194 



Efficient estimates, 123, 160 

 Elastic prices, 232 



Empirical distribution, of chi-square, 133 

 of correlation coefficient, 218 

 of difference between sample means, 



176 

 of sample means, 155, 157 

 of t, 9 D/F, 162 

 of z, 219 

 Error of the first kind, 116 

 Error of the second kind, 116 

 Estimated average Y for a given X, 204, 



206 

 Estimation, of the linear correlation co- 

 efficient, 217 

 of the linear regression coefficient, 



205, 211 

 of the mean of a normal population, 



160 

 of the mean Y for a given X, 204, 212 

 of the percentage, p, for a binomial 



population, 122 

 of the standard deviation, about the 

 linear trend line, 210 



Estimation, of the standard deviation, 

 of the regression coefficient, b, 211 

 of the sample mean, 161 

 of X, 160 

 point, 122 

 unbiased, 122 

 Events, dependent, 55 

 exhaustive set of, 51 

 independent, 54 

 mutually exclusive, 53 

 Expected gain or loss, 71 

 Expected number, 70 



Factorial n, 64 



Finney, K. F., 221 



Fisher, R. A., 5, 219 



Foster, Jackson W., 45 



Frequency curve for, chi-square with 1 

 D/F, 133 

 cumulative standard normal, 96 

 cumulative t with 4 and 24 D/F, 163 

 sample correlation coefficient, 10 D/F, 



219 

 standard normal, 93 

 t with 9 D/F, 162 



Frequency distribution tables, 23 



Freund, John E., 48, 242 



(?-test for, one random sample, 182 



two random samples, 183 

 Galileo, 3 



Galton, Sir Francis, 3, 226 

 Geometric mean, 20 

 Gosset, William Seely ("Student"), 4 

 Grading on the curve, 97 

 Grant, Eugene L., 152 

 Graunt, John, 2 

 Guinea pig gains, table, 39 

 Guinea pig weights, table, 38 



Hald, A., 112, 191, 242 

 Harmonic mean, 21 



Ibsen, H. L., 38 



Independent events, 54 



Inference, statistical, 114 



Interval estimate, of average Y for a 

 given X, 213 

 of correlation coefficient, 220 

 of population mean, 164, 166 



