standard_description: Solve systems of linear equations exactly and approximately (e.g., with graphs), focusing on pairs of linear equations in two variables.
problem_activity: Task
Bob’s Bagel Shop has estimated the following probabilities for the number of bagels a randomly-selected customer buys when he or she enters the shop.
| No. of Bagels | Probability |
|---------------|-------------|
|       1       |     .5      |
|       2       |     .1      |
|       3       |     .1      |
|       6       |     .1      |
|      12       |     .2      |
Bob sells bagels for \$0.80 each, or \$9.00 for a dozen. If $X =$ the amount of money Bob collects from a randomly-selected customer, find and interpret the expected value of $X$.


aligns: no