The following are advertised sale prices of hard disk drives on Amazon’s website for various capacity hard drives.
| Hard Disk Drive Capacity (in terabytes) | Sale Price ($) |
| 9 | 147 |
| 20 | 197 |
| 27 | 297 |
| 31 | 447 |
| 35 | 1177 |
| 40 | 2177 |
| 60 | 2497 |
- Decide which variable should be the independent variable and which should be the dependent variable.
- Draw a scatter plot of the data.
- Does it appear from inspection that there is a relationship between the variables? Why or why not?
- Calculate the least-squares line. Put the equation in the form of: ŷ = a + bx
- Find the correlation coefficient. Is it significant?
- Find the estimated sale price for a 32 terabyte hard drive. Find the cost for a 50 terabyte hard drive.
- Does it appear that a line is the best way to fit the data? Why or why not?
- Are there any outliers in the data?
- What is the slope of the least-squares (best-fit) line? Interpret the slope.
OpenStax Introductory Statistics 2e, 12.6 Outliers, exercise 24