The following table shows the ratings of item xi by user uj. Use the algorithm proposed in [ResnickISBR94] to predict the rating of item x3 by user u2. To receive any credit at all, you must show the intermediate steps of the calculation.
| u1 | u2 | u3 | u4 | |
| x1 | 1 | 2 | 2 | 3 |
| x2 | 3 | 5 | ||
| x3 | 2 | ? | 3 | 4 |
| x4 | 4 | 3 | 3 | |
| x5 | 5 | 1 |