11.10

Suppose half of all the transactions in a clothes shop purchase jeans, and one-third of all transactions in the shop purchase T-shirts. Suppose also that half of the transactions that purchase jeans also purchase T-shirts. Write down all the (nontrivial) association rules you can deduce from the above information, giving support and confidence of each rule.

Here is what we know: * 50% of all transactions purchase jeans. * 33.33% of all transactions purchase T-shirts. * 50% of all transactions that purchase jeans also purchase T-shirts.

Possible association rule:

  1. jeans => T-shirts
    • Support: 25% <= support <= 33.33%
    • Confidence: 50%
  2. T-shirts => jeans
    • Support: 25% <= support <= 33.33%
    • Confidence: We cannot say anything here