MS 150 Statistics prequiz fall 2006 • Name:

Basic statistics: Seven teams of four students counted the number of covered sidewalk posts at Kosrae High School on the 19^th of July 2006. The number of posts recorded by the students is recorded in the table on the right.

1. _________ Is the level of measurement for the data nominal, ordinal, or ratio?
2. _________ Determine the sample size n for the post data.
3. _________ Determine the median for the post data.
4. _________ Determine the mode for the post data.
5. _________ Determine the minimum count for the post data.
6. _________ Determine the maximum count for the post data.
7. _________ Calculate the range.
8. _________ Calculate the sample mean x.
9. _________ Calculate the sample standard deviation sx for the post data.
10. _________ Calculate the sample Coefficient of Variation.

Linear regression: The same 28 students rolled a tennis ball along the 15 meter long covered walkway between the English classrooms and the math classrooms. As the ball rolled, a stopwatch was used to time the ball rolling past chalk marks on the sidewalk at three meter intervals. The data is in the table on the right.

11. Plot the coordinates on the graph provided.
12. Draw a best fit line through the points.
13. ________ Determine the slope for the best fit line.
14. ________ Find the y-intercept for the best fit line using the graph.
    
15. ________________________ Write the best fit line in y = mx + b slope-intercept form.
16. ________ What would be the predicted distance after nine seconds?
17. ________ What would be the predicted time for the ball to travel 45 meters?