# Mortlocks • Name:

Essay
Score
11
11
3
27
23
5
25
5
8
23
19
34
14
14
11
13
23
0
0
4
8
0
0
4
0
0
0
1
0
7

## Part I: Basic Statistics

A new high school took the entrance test this year, Mortlocks High School. Thirty seniors from Mortlocks High School took the entrance test. The inaugural graduation class included Aaron, Airon, Akim, Barbara, Benony, Cabella, Eddy, Garry, Isabella, Jaymar, Jayson, Jerbet, Joncy, Julius, Kurata, Lorlin, Maptin, Mayson, Menchor, Merista, Molly, Phanchy, Richy, Robsan, Setirick, Smalreen, Swancy, Tricia, Valerio, Wilson.

The essay section is marked out of fifty points. A zero means the essay was off-topic, not in English, or otherwise severely flawed. This year the typical successful associate's admission candidate scored a 34 or higher on the essay. The national mean across all schools and campuses in all states on the essay this year was 24.14.

For the data in the table, calculate the following statistics.

1. _________ What level of measurement is the data?
2. _________ Determine the sample size n.
3. _________ Determine the minimum.
4. _________ Determine the maximum.
5. _________ Calculate the range.
6. _________ Calculate the midrange.
7. _________ Determine the mode.
8. _________ Determine the median.
9. _________ Calculate the sample mean x.
10. __________________ Is the sample mean for Mortlocks High School above or below the national mean?
11. _________ Calculate the sample standard deviation sx.
12. _________ Calculate the sample Coefficient of Variation.
13. __________________ Use the sample mean x and sample standard deviation sx for Mortlocks High School calculated above to calculate the z-score for a student with a score of 0 on their essay.
14. _________ Is the z-score for a student with a score of 0 an ordinary or extraordinary value for students at Mortlocks High School?
15. __________________ Use the sample mean x and sample standard deviation sx for Mortlocks High School calculated above to calculate the z-score for the one student with a score of 34 on their essay.
16. _________ Is the z-score for the student with a score of 34 an ordinary or extraordinary value for a student at Mortlocks High School?
17. Looking at the statistics for this high school, what overall conclusions might we draw about the quality of the essays produced by Mortlocks High School?

## Part II: Linear regression

Data was gathered for the volume and mass of marbles of different sizes.

Volume (cm³)Mass (g)
0.61.7
1.74.4
7.418.6
21.653.8

Data table

1. ______________ Does the relationship appear to be linear, non-linear, or random?
2. ______________ Determine the slope of the best fit line for the data.
3. ______________ Determine the y-intercept of the best fit line for the data.
4. ______________ Is the nature of the relation positive, negative, or neutral?
5. ______________ Calculate the linear correlation coefficient r for the data.
6. ______________ Is the correlation none, weak/low, moderate, strong/high, or perfect?
7. ______________ Use the slope and intercept above to calculate the predicted mass for a marble with a volume of 15 cm³.
8. ______________ Use the slope and intercept to solve for the volume of a marble that has a mass of 45 g.