Answer:
Step-by-step explanation:
Given that customers at a gas station pay with a credit card (A), debit card (B), or cash (C).
To find out the mean and variance of the number who pay with a debit card for 100 customers
We can sort persons using a debit card or not. Thus there are two outcomes with p = success for each trial =0.6
Because we are interested in whether or not a debit card was used, we can use the binomial distribution. X = the number of customers who use a debit card out of 100 customers
Mean = np = 60 and variance =npq = 24
Similarly for no of customers do not pay with cash is binomial with p = 0.8
Mean = 80 and variance =16