Statistics work

Formal Writing Assignment 2 Prof. Yeung

Correlation & Regression Project/Formal Writing Assignment

Assignment details: In this project, you will discuss what correlation is, what regression lines are,

and how each can be determined. You will also be given various sets of data for which you will

determine and describe what type of correlation exists. Additionally, you will find regression

lines for sets of data and use them to predict other data values.

Your project should include:

PART 1 – EXPLANATION OF CONCEPTS

This is the paper portion of your project. Please include the following discussions/explanations

in a paper format (organized into complete sentences & paragraphs, correct grammar & spelling,

etc.)

A) A detailed explanation of correlation. Include in your explanation: a definition of correlation, the different types of correlation, how you can determine the type of

correlation by looking at a scatter plot, and how you can determine the type of correlation

by computing the value of the correlation coefficient, r. Include in your explanation both

how the direction and the strength of the correlation can be determined. Include

examples to illustrate your explanations.

B) An explanation of what a regression line is. Describe how it is found and what it can be used for.

C) A discussion of the distinction between correlation and causation with respect to data sets. Clearly explain the difference and include examples in your explanation.

PART 2 – CALCULATIONS

For each of the following 5 data sets provided to you, please do the following.

A) Use Excel to construct a scatter plot and compute the value of the correlation coefficient.

Additionally, the 1st and 3rd given data sets have a significant correlation. For these two

data sets, also use Excel to

• Add the regression line to your scatterplot

• Find the equation of the regression line

B) Give an explanation of the type of relationship that exists between the two variables. This explanation should include:

• Say whether there is a strong positive linear correlation, weak positive linear correlation, strong negative linear correlation, weak negative linear correlation, or

no linear correlation between the two variables.

• Describe how you can see this from the scatter plot and from the value you found for the correlation coefficient.

• Interpret this relationship in the context of the problem.

Formal Writing Assignment 2 Prof. Yeung

Additionally, for the 1st and 3rd given data sets use your regression line to predict a y-

value for the given x-value, and write a sentence explaining this prediction.

o Data set #1 : use x = 7 o Data set #3 : use x = 40

Additional Information:

• Your project should be typed (no hand-written projects!).

• Include all of the sets of data and scatter plots in your report (these can all be copied and pasted into Word from Excel).

• You may reference the textbook, Chapter 9.1 and 9.2, to help with your definition/descriptions.

• You are required to cite one outside source beside the use of the textbook

• All concepts should be explained in your own words! Grading: The formal written report will be part of your writing assignments grade. It will be worth 6% of

your final course grade. I will judge the essay on the following criteria:

Style, clarity, and mechanics of writing Your understanding of the statistical topics in the article and your ability to convey them Citation formatting

Please refer to the rubric for more details.

Due date: Final draft and the tutor’s comments from your first draft must be submitted on Blackboard

BY THE END OF THE DAY on Sunday, April 4, 2021.

Data Sets:

1. The data below consist of the test scores of nine randomly selected students and the number of hours they studied for the test.

Hours, x 5 10 4 6 10 9 2 8 4

Test Score, y 64 78 72 80 95 87 55 76 59

2. A study was conducted to compare the average time spent in the lab each week (in hours) versus the course grade received for computer students.

Hours, x 10 11 16 9 7 15 16 10 13 7

Grade, y 82 51 62 58 89 81 46 63 65 77

3. A researcher wishes to determine whether a person’s age is related to the number of hours he or she jogs per week.

Age, x 34 22 48 56 62

Hours, y 5.5 7 3.5 3 1

4. The data below show the cost of advertising, in dollars, and the number of products sold for each of eight randomly selected product lines.

Formal Writing Assignment 2 Prof. Yeung

Cost, x 9000 2000 3000 4000 2000 5000 7000 10000

Number

Sold, y

85000 52000 82000 68000 67000 72000 83000 73000

5. The data below show the temperature and the amount a plant grew, in millimeters, for each of nine randomly selected days.

Temperature, x 62 76 50 51 71 46 51 44 79

Growth, y 36 39 50 13 33 33 17 12 16