Children in two elementary school classrooms were given two versions of the same test, but with the order of questions arranged from easier to more difficult in version a and in reverse order in version b. randomly selected students from each class were given version a and the rest version b. the results are shown in the table. n latex: \overline{x} x ¯ s version a 31 83 4.6 version b 32 78 4.3(a) a 90% confidence interval for the difference in the means of the populations(b) at the 1% significance level, will you conclude that the a version of the test is easier than the b version (even though the questions are the same)? 2. a study to compare the mean level of ldl cholesterol in male and female students who do not exercise regularly gave the data shown in the table. we may assume that the populations of ldl level are normally distributed. nlatex: \overline{x}x¯ smale3510931female609626a 90% confidence interval for the difference in mean ldl cholesterol level between mean and women is13 ± 8.313 ±11.613 ± 9.813 ± 10.513 ± 7.6