The accompanying table shows, for credit-card holders with one to three cards, the joint probabilities for number

Question:

The accompanying table shows, for credit-card holders with one to three cards, the joint probabilities for number of cards owned (X) and number of credit purchases made in a week (Y).

a. For a randomly chosen person from this group, what is the probability distribution for number of purchases made in a week?
b. For a person in this group who has three cards, what is the probability distribution for number of purchases made in a week?
c. Are number of cards owned and number of purchases made statistically independent?

Distribution
The word "distribution" has several meanings in the financial world, most of them pertaining to the payment of assets from a fund, account, or individual security to an investor or beneficiary. Retirement account distributions are among the most...