The contingency table below shows the number of credit cards owned by a group of individuals below the age of 35 and above the age of 35.
| Zero | One | Two or more | Total | |
|---|---|---|---|---|
| Between the ages of 18-35 | 9 | 5 | 19 | 33 |
| Over age 35 | 18 | 10 | 20 | 48 |
| Total | 27 | 15 | 39 | 81 |
If one person was chosen at random:
What is the probability they had no credit cards?
What is the probability they had one credit card?
What is the probability they had no credit cards and is over 35?
What is the probability they are between the ages of 18 and 35, or have zero credit cards?
What is the probability they had no credit cards given that they are between the ages of 18 and 35?
What is the probability they have no credit cards given that they are over age 35?
Does it appear that having no credit cards depends on age? Or are they independent? Use probability to support your claim.
Lee et al., Math in Society, §4.1 Contingency Tables, Exercise 9