Answer:
0.50
Step-by-step explanation:
The probability that a customer has purchased a cup of coffee given that they have also purchased a piece of cake is determined by the percentage of customers who purchase both coffee and cake (20%) divided by the percentage of customers who purchase cake (40%):
[tex]P(Coffee|Cake) = \frac{P(Coffee\cap Cake)}{P(Cake)}\\P(Coffee|Cake) =\frac{0.20}{0.40}=0.50[/tex]
50% of the customers also purchased coffee given that they have purchased a piece of cake.