During a promotional campaign, a cell phone dealer allows purchasers of new cell phones to return them within 30 days if they are dissatisfied with their purchases for any reason. The cost to the dealer of such a refund is $100. The dealer estimates that 30% of all purchasers will return the cell phones and receive refunds. Suppose that 20 cell phones are purchased. What is the probability that more than 3 cell phones will be returned? Answer to 2 decimal places. 

"Get 15% discount on your first 3 orders with us"
Use the following coupon
FIRST15

Order Now