Question description
Height & Weight: Erroneous Data
As we discussed in chapter 10, sometimes an outlier can make or break a correlation. Data from 11 people regarding height and weight is given in the table below.
x = height in inches | y = weight in pounds |
60 | 120 |
72 | 200 |
64 | 130 |
71 | 205 |
68 | 180 |
69 | 180 |
69 | 193 |
70 | 195 |
62 | 115 |
62 | 140 |
5.5 | 160 |
Question 3:
Part A
- Use software to determine the regression equation for predicting weight from height, using α = 0.05.
- What is the regression equation? Make sure you show your work and/or copy and paste your output into the body of your post.
- State the software you used to produce the regression equation.
- Clearly identify the values for the slope and the y-intercept.
- What is the expected weight for a person who is 62 inches tall?
Part B
- Use software to calculate the regression equation for predicting weight from height, excluding the last data point corresponding to a height of 5.5 inches (as the entry of 5.5 inches seems to be an error),using α = 0.05.
- What is the regression equation without the last data point? Make sure you show your work and/or copy and paste your output into the body of your post.
- Clearly identify the values for the slope and the y-intercept.
- Using the regression equation with the last data point excluded, what is the expected weight for a person who is 62 inches tall?
- Compare your results to those obtained in part A. What can you say about how excluding the outlier affected your results?