Answer:
Assuming that the $1 bill was pulled at random, then the expected value of the amount chosen is
.
Step-by-step explanation:
From the given question, the bag contains;
$1 bill = 7
$5 bill = 1
$10 bill = 3
$20 bill = 2
Total number of bills in the bag = 13
Pulling a bill at random, the bills would have an expected value as follows:
For $1 bill, the expected value = 
For $5 bill, expected value = 
For $10 bill, expected value = 
For $20 bill, the expected value = 
Assuming that the $1 bill was pulled at random, then the expected value of the amount chosen is
.