Lesson 8
Analyzing Bivariate Data
Problem 1
Different stores across the country sell a book for different prices. The table shows the price of the book in dollars and the number of books sold at that price.
price in dollars | number sold |
---|---|
11.25 | 53 |
10.50 | 60 |
12.10 | 30 |
8.45 | 81 |
9.25 | 70 |
9.75 | 80 |
7.25 | 120 |
12 | 37 |
9.99 | 130 |
7.99 | 100 |
8.75 | 90 |
![A blank coordinate plane with 21 horizontal units and 29 vertical units.](https://cms-im.s3.amazonaws.com/Q42Pte5537RJ6WmPCa9j57mE?response-content-disposition=inline%3B%20filename%3D%228-8.6.A1.Image.03.b.png%22%3B%20filename%2A%3DUTF-8%27%278-8.6.A1.Image.03.b.png&response-content-type=image%2Fpng&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAXQCCIHWF3XOEFOW4%2F20240630%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20240630T171749Z&X-Amz-Expires=604800&X-Amz-SignedHeaders=host&X-Amz-Signature=fc005d34375f469351825d88c543808656f411b1fefc6d48a5e899c7980b3245)
- Draw a scatter plot of this data. Label the axes.
- Are there any outliers? Explain your reasoning.
- If there is a relationship between the variables, explain what it is.
- Remove any outliers, and draw a line that you think is a good fit for the data.
Solution
Teachers with a valid work email address can click here to register or sign in for free access to Formatted Solution.
Problem 2
Here is a scatter plot:
![A scatterplot, age in weeks, weight in pounds. From origin, points trend up & right with a consistent slope to around 24 comma 60. From x = 30 to x = 120, points are clustered around the line y = 60.](https://cms-im.s3.amazonaws.com/Coej3wyWsRbWf9SpbfUrNJju?response-content-disposition=inline%3B%20filename%3D%228-8.6.B7.PP.doberman2.png%22%3B%20filename%2A%3DUTF-8%27%278-8.6.B7.PP.doberman2.png&response-content-type=image%2Fpng&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAXQCCIHWF3XOEFOW4%2F20240630%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20240630T171749Z&X-Amz-Expires=604800&X-Amz-SignedHeaders=host&X-Amz-Signature=a3c09f88f82af82418e1d4f7d3305cb32ed683023074eee9b5322bd7a2b1d1d9)
Select all the following that describe the association in the scatter plot:
Linear association
Non-linear association
Positive association
Negative association
No association
Solution
Teachers with a valid work email address can click here to register or sign in for free access to Formatted Solution.
(From Unit 6, Lesson 7.)Problem 3
Using the data in the scatter plot, what can you tell about the slope of a good model?
![A scatterplot. Horizontal, from 1980 to 2020, by 10’s. Vertical, from 90 to 115, by 5’s. 14 data points trend slightly linearly downward and right.](https://cms-im.s3.amazonaws.com/UqPz2aM5XqX6E2dyP9Lu3Xcu?response-content-disposition=inline%3B%20filename%3D%228-8.6.PP.B.Image.31.png%22%3B%20filename%2A%3DUTF-8%27%278-8.6.PP.B.Image.31.png&response-content-type=image%2Fpng&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAXQCCIHWF3XOEFOW4%2F20240630%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20240630T171749Z&X-Amz-Expires=604800&X-Amz-SignedHeaders=host&X-Amz-Signature=ccc11e4a466aad4e214895b7116a7a067b64dc0fed37a08845fb24d414be9eef)
The slope is positive.
The slope is zero.
The slope is negative.
There is no association.
Solution
Teachers with a valid work email address can click here to register or sign in for free access to Formatted Solution.
(From Unit 6, Lesson 6.)