Aphone company determined that a higher income indicates that a customer has a more expensive calling plan. what does the analysis show?

The analysis shows that there is a positive correlation between income and cost of calling plan. But it does not always mean that there is causation. Further studies needs to be carried out in order to determine whether there is a causation. Always remember that causation is not equal to correlation!

The probability of not drawing a black marble is 8:2
The probability of drawing a red marble is 3:10