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2.38 Baggage fees: An airline charges the following baggage fees: $25 for the first bag and $35 for the second. Suppose 54% of passengers have no checked luggage, 34% have only one piece of checked luggage and 12% have two pieces. We suppose a negligible portion of people check more than two bags.

The standard deviation of baggage-related revenue is: $ ?    (please round to the nearest cent)

about how much revenue should the airline expect for a flight of 120 passengers? $

please round to the nearest dollar 

please help

Mrs. Donovan is the coach of a middle school golf team that has 10 golfers. There are 2 sixth graders, 2 seventh graders, and 6 eighth graders on the team. Mrs. Donovan will randomly select two team captains.

What is the probability that both captains will be eighth graders?

Make sure to write your answer as a reduced fraction.  need help

Every cereal box has a gift inside, but you cannot tell from the outside what the gift is. The store manager assures you that 17 of the 57 boxes on the shelf have the secret decoder ring. The other 40 boxes on the shelf have a different gift inside. If you randomly select two boxes of cereal from the shelf to purchase, what is the probability that BOTH of them have the secret decoder ring?

(Give answer as a decimal correct to at least three decimal places.) Please help