Exercise

# Further refinement with lift

Once again, you report your results to the library: Use *Twilight* to promote *Harry Potter*, since the rule has a higher confidence metric. The library thanks you for the suggestion, but asks you to confirm that this is a meaningful relationship using another metric.

You recall that lift may be useful here. If lift is less than 1, this means that *Harry Potter* and *Twilight* are paired together less frequently than we would expect if the pairings occurred by random chance. As with the previous two exercises, the DataFrame `books`

has been imported for you, along with `numpy`

under the alias `np`

.

Instructions

**100 XP**

- Compute the support of
*{Potter, Twilight}*. - Compute the support of
*{Potter}*. - Compute the support of
*{Twilight}*. - Compute the lift of
*{Potter}*\(\rightarrow\)*{Twilight}*.