You are interested in determining the difference in two population means. You select a random sample of eight items from the first population and eight from the second population and then compute a 95% confidence interval. The sample from the first population has an average of 12.2 and a standard deviation of 0.8. The sample from the second population has an average of 11.7 and a standard deviation of 1.0. Assume that the values are normally distributed in each population and that the population variances are approximately equal The corresponding critical t value is O 1.753 O 1.761 O 2.120 O 2.131 O 2.145