The Datafile

• sat_ihs.dsk: SAT@IHS data file.

The Assignment

Your assignment is to answer the questions below. For each, you should

Create appropriate hypotheses

Have DataDesk run the test ‡ (at the 5% level of significance)

Print out the result

Carefully state your conclusion in context.

Some help with DataDesk

• For a one sample t -test, start by selecting the appropriate variables as Y . For a 2-sample or matched pairs test, select the two variables of interest as Y and X .
• To perform an hypothesis Test , go to the Calc menu.
• Be sure to pick the t -procedure appropriate for the question you are trying to answer: one sample (individual), matched pairs, or 2 independent samples.
• Specify the hypothesized value of the parameter in the null hypothesis box, and then choose the appropriate lower-tail, upper-tail, or two-tailed alternative.
• To test for gender-based differences, you must first select the variable of interest ( Verbal for example) as Y , and Gender as X . Then Manip → Split into Variables by Group . This will give you two new variables, Verbal.1 for boys' scores, and Verbal.2 for the girls' scores.

The Questions

1. Do Ithaca High students score significantly higher on the SAT-Verbal than the national average of 505?
2. Do Ithaca High students score significantly higher on the SAT-Math than the national average of 514?
3. Is there a significant difference between the Verbal and math scores of Ithaca High students? If so, create a confidence interval to help you explain which average is higher and by how much.
4. Is there a significant difference in performances of IHS boys ( Gender = 1) and girls ( Gender = 2) on the Verbal exam? If so, create a confidence interval to help you explain which average is higher and by how much.
5. Is there a significant difference in the performances of IHS boys and girls on the Math exam? If so, create a confidence interval to help you explain which average is higher and by how much.