生物统计学上机操作复习题-Data for test1.doc

Species A Species B 315.5 342.6 333.5 367.1 342.2 374.3 358.8 399.3 372.2 402.5 399.8 411.5 401.5 422.4 433.7 436.6 440.2 475.3 Part two: Statistical analyses (60%) Here is an example (see the left table) of fore-limb length (mm) of two hypothetical species of mammals in captivity. Please examine if there is a between-species difference in the mean fore-limb length using Student’s t-test, Mann-Whitney U-test and one-way ANOVA Species A =Species B t = -2.00, df = 16, P = 0.062：差异不显著 U = 18.00, P = 0.051：差异不显著 F1,16 = 4.02, P = 0.062：差异不显著 1.2、Using the data in the left table to test the null hypothesis that the academic performance of students is the same under the two teaching assistants by using Mann-Whitney U-test Teaching assistant A Teaching assistant B Grade Rank of grade Grade Rank of grade A+ 1 A 4 A 4 A 4 A 4 A 4 A( 8 B + 10 A( 8 B 12 A( 8 B 12 B 12 B( 14 C+ 15.5 C 18.5 C+ 15.5 C 18.5 C 18.5 C( 21.5 C 18.5 D 25 C( 21.5 D 25 D 25 D 25 D( 28.5 D 25 D( 28.5 U = 83; P = 0.337; 差异不显著 The following sample data are recorded as the observed frequencies (O), by which you may use to test: H0: The sample comes from a population having a 9: 3: 3: 1 color pattern of Red Rayed to Red margined to Blizzard to Rayed flowers; HA: The sample comes from a population not having a 9: 3: 3: 1 ratio of the above four flower phenotypes. You are asked: (1) to show the expected frequencies (E), (2) to decide the trueness of the null hypothesis (H0) using Chi-square goodness of fit (X2 test) and Log-likelihood ratio (G-test). Please note that the critical value is 7.815 when P = 0.05 and df = 3. Red Rayed Red margined Blizzard Rayed n O 155 42 45 8 250 E 140.6 46.9 46.9 15.6 250 X2 test: X2 = 5.766, df = 3, P 0.05 G-test: G = 6.550, df = 3, P 0.05 The appendix is a set of data on the effects of thermal and hydric environments on incubation period and hatchling (孵出幼体) traits of the Chinese cobra, Naja atra（舟山眼镜蛇）. You are as