1. A study determined that 6% of persons age 65 to 74 have a certain symptoms. A group of 18 persons age 65 to 74 are selected at random. Find the probability that at least 2 persons have the symptoms.
2. A contest at a fast-food restaurant offered the following cash prizes and probabilities of wining on one visit when a customer buys an order of French fries for $1.21. Find the expected winnings if the player buys 22 orders of French fries in multiple visits.
|
Prize
|
Probability
|
|
$100,000
|
1/8,504,860
|
|
$50,000
|
1/302,500
|
|
$10,000
|
1/282,735
|
|
$1,000
|
1/153,560
|
|
$100
|
1/104,560
|
|
$25
|
1/9,540
|
What are the expected winnings if the player buys 22 orders of French fries on multiple visits?
3. 10.6% of the population is 65 or older. Find the probability that the following numbers of persons selected at random from 50 peopple are 65 or older.
4. A study determined that the 3% of children less than 18 year of age live with their father only. Find the probability that at least3 percent person selected at random from 12 children less than 18 year of age lived with their father only.
5. A coin tossed 5 times. Find the probability of getting at most 2 heads.