## Dr. Wilson

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1. A gambler suspects that a die is loaded. She rolls the die 60 times and gets the following results.

 Face 1 2 3 4 5 6 Count 24 7 8 9 7 5

• State the null hypolthesis
• Use a Chi square test.

2. A study was conducted to see if a student's year in school had any effect on how well they did in their classes. The following data for all the students in all their classes was obtained from the Registrar.

 A B C D F Fresh 1569 1567 1214 432 987 Soph 1484 1581 1322 212 643 Jun 1592 1609 1472 153 421 Sen 1685 1623 1211 75 315

Use a chi-square test to determine if there is a significant difference between the grades received by students in different classes.

3. An Environmental Studies class did a survey to determine the relation between engine size and fuel consumption. They obtained the following data for five types of cars.

 Car Size MPG A 1.6 38 B 1.8 29 C 2.2 32 D 3.2 24 E 4.7 17

where the engine size is given in liters and the mileage is given in miles per gallon. The question is whether engine size has an effect on gasoline mileage.

• a) State the null hypotheses and the alternative hypothesis
• b) Find the line of best least squares fit.
• c) Test the null hypothesis.
• d) Give a 95% confidence interval for the slope in the regression equation.
• e) Give a 95% confidence interval for the mileage that a car with a 2 liter engine would get.