21.30 Height and the big picture. Forty-six college students were randomly divided into two groups of size 23. One group was asked to imagine being on the upper floor of a tall building and the other on the lowest floor. Participants were then asked to choose between a job that required more detail orientation versus a job that required a more big-picture orientation. They rated their job preferences on an 11- point scale, with higher numbers corresponding to a greater preference for the big-picture job. Here are the summary statistics: Group Group Size Mean Standard Deviation Low 23 4.61 3.08 High 23 6.68 3.45 (a) What degrees of freedom would you use in the conservative two-sample z procedures to compare the lower and higher floor groups? (b) What is the two-sample t test statistic for comparing the mean job preference ratings for the two groups? (c) Test the null hypothesis of no difference between the two population means against the two-sided alternative. Use your statistic from part (b) with degrees of freedom from part (a)