22. Determinations of saliva pH levels were made in two independent random samples of seventh-grade schoolchildren. Sample A children were caries-free while sample B children had a high incidence of caries. The results were as follows: A: 7.14. 7.11. 7.61. 7.98. 7.21. 7.16. 7.89 B: 7.36. 7.04. 7.19. 7.41. 7.10. 7.15. 7.36. 7.24. 7.86. 7.47. 7.82. 7.37. 7.66. 7.62. 7.65 7.57. 7.64. 7.00. 7.25. 7.19 Construct a 90 percent condence interval for the difference between the population means. Assume that the population variances are equal. Chapter 6 Review Question 22 (pg 184 'IOth edition) Using the data in the above question cconstruct a 90% condence interval for the ratio of the variances. The lower bound for the Ci is and the upper bound is _ Round to two decimals