Costco sells paperback books in their retail stores and wantedto examine the relationship between price and demand. The price ofa particular novel was adjusted each week and the weekly sales wererecorded in the table below.
| Sales | Price |
| 3 | $12 |
| 4 | $11 |
| 6 | $10 |
| 10 | $9 |
| 8 | $8 |
| 10 | $7 |
Management would like to use simple regression analysis toestimate weekly demand for this novel using the price of the novel.The 95% confidence interval that estimates the average weekly salesfor a price of $9 is ________.
