Compute a 90% confidence interval for the expected change in sales due to the product placement. Show your working. 2. Interpret the confidence interval. 3. Do you need to make any assumptions in order for your confidence interval to be valid?
A market researcher is interested in knowing whether placing a product at the checkout of a supermarket, in addition to the shelves, leads to an increase in sales which persists after the product is removed from the checkout. A random selection of pairs of supermarkets is chosen. In one of each of the pairs, the product is placed at the checkout for one week. Sales of the product in all the supermarkets were recorded before and after the placement of the product at the checkout, the change in the differences between each pair were computed, and resulting data were saved in this file.
1. Compute a 90% confidence interval for the expected change in sales due to the product placement. Show your working.
2. Interpret the confidence interval.
3. Do you need to make any assumptions in order for your confidence interval to be valid?
| x |
| 3.48983 |
| 4.94556 |
| 4.052113 |
| 4.472282 |
| 5.540868 |
| 4.208772 |
| 6.008711 |
| 4.498776 |
| 3.686976 |
| 7.076072 |
| 4.076262 |
| 5.238185 |
| 5.09588 |
| 4.880026 |
| 5.672237 |
| 4.425734 |
| 4.782259 |
| 5.481968 |
| 4.766603 |
| 3.500491 |
| 4.926119 |
| 4.636897 |
| 4.053717 |
| 4.659856 |
| 5.573215 |
| 4.553886 |
| 5.341466 |
| 4.587203 |
| 5.053699 |
| 4.615279 |
| 5.320065 |
| 3.766877 |
| 5.553998 |
| 2.387624 |
| 3.358401 |
| 4.476138 |
| 3.567032 |
| 4.347241 |
| 4.852802 |
| 2.978478 |
| 2.212243 |
| 4.52846 |
| 4.085874 |
| 3.475987 |
| 2.372552 |
| 5.735534 |
| 5.310185 |
| 4.878427 |
| 4.912741 |
| 8.347768 |
| 4.080804 |
| 4.003875 |
| 6.410899 |
| 5.897793 |
| 6.182137 |
| 3.472553 |
| 3.682343 |
| 5.705827 |
| 5.490506 |
| 5.401305 |
| 5.524495 |
| 4.694655 |
| 5.683393 |
| 6.00022 |
| 1.450137 |
| 3.479706 |
| 5.256608 |
| 4.359963 |
| 5.393565 |
| 4.775363 |
| 2.478408 |
| 3.911031 |
| 2.489546 |
| 6.528131 |
| 4.220879 |
| 6.161974 |
| 3.096381 |
| 3.895005 |
| 6.302606 |
| 5.074283 |
| 4.246096 |
| 6.37448 |
| 6.505191 |
| 3.356179 |
| 5.868444 |
| 4.714592 |
| 3.906634 |
| 3.203439 |
| 4.367217 |
| 5.689892 |
| 5.876155 |
| 4.79045 |
| 3.357541 |
| 4.205848 |
| 2.367392 |
| 4.565555 |
| 4.680084 |
| 5.001616 |
| 5.366056 |
| 7.376426 |
| 4.241905 |
| 2.582907 |
| 2.953644 |
| 4.866225 |
| 3.782098 |
| 3.76539 |
| 6.049075 |
| 5.560586 |
| 6.295615 |
| 4.692865 |
| 4.742452 |
| 6.297748 |
| 3.383473 |
| 3.768315 |
| 4.512378 |
| 5.575764 |
| 5.852807 |
Trending now
This is a popular solution!
Step by step
Solved in 3 steps with 2 images
