Ch. 7 



REVIEW PROBLEMS 



235 



27. Solve as in problem 26 for the higher income group of fathers. 



28. You might wonder if the group which refused (or neglected) to reveal 

 the fathers income are from a different population as regards scores in critical 

 thinking. Make a study of this matter for freshmen women by means of the 

 G-test. Ans. Low income vs. undeclared: G = 0.26, P < .010. 



High income vs. undeclared : G = 0.09, P » .10. 



29. Do freshmen women from the higher income group belong to a population 

 with a lower mean score than that of the freshmen women from the lower 

 income group? Use the G-test. 



30. Solve problem 29, using the t-test instead of the G-test. (See other tables 

 for these D/F.) Given: 2z 2 for (1) = 804.80; for (2) = 953.80. 



Ans. t = 1.16, 38 D/F, P > .05. 



31. Use the G-distribution to set a 90 per cent confidence interval on the true 

 mean score of freshmen men whose fathers make $5000 or less per year. Does 

 this interval make it possible to test the hypothesis H (fi = 0)? 



32. Compute CI 90 's on the true means of the populations sampled by columns 

 4 and 6 (from left) in the table above, and draw all appropriate conclusions. 



Ans. Col. 4: 33.2^^ — 37.6. Col. 6: 27.7 ^^ — 32.1 by G-distribution. 

 The following data record the thiamin-content, in micrograms per gram of 

 meat (dry fat-free basis) in raw pork loin after various periods of storage (tem- 

 perature not over 10°F). (These data made available through the courtesy of 

 Dr. Beulah Westerman, Department of Foods and Nutrition, Kansas State 

 College.) 



Period of Storage 



12 



(Weeks) 

 24 



40 



56 



72 



33. Compute through the G-distribution the CI 90 on the true thiamin con- 

 centration (micrograms per gram) in raw, unstored, pork loin produced under 

 the conditions maintained during the sampling which produced the above data. 

 Draw all appropriate conclusions. 



34. Solve as in problem 33 for raw pork loin stored 12 weeks. 



Ans. CI 90 : 76.9 ^ fi ±= 99.1 micrograms per gram. 



35. Does cold storage (at, or below, 10°F) of raw pork loin for 12 weeks re- 

 duce the thiamin concentration, according to the evidence from the above 

 data and the G-test? 



