Basic Terms of Probability

1. Basic Terms of Probability

2. Objectives • Determine the probability of a given event . • Determine the odds of a given event. • Use a Punnet square to determine probability.

3. Vocabulary • experiment • sample space - the set S of all possible outcomes of an experiment • event – any subset E of the sample space S • probability – success divided by total • odds – success to failures

4. Formulas

5. A jar on your desk contains twelve black, eight red, ten yellow, and five green jellybeans.  You pick a jellybean without looking. What is the probability that the jellybean is green?

6. A jar on your desk contains twelve black, eight red, ten yellow, and five green jellybeans.  You pick a jellybean without looking. What is the probability that the jellybean is not yellow?

7. A jar on your desk contains twelve black, eight red, ten yellow, and five green jellybeans.  You pick a jellybean without looking. What are the odds in favor of picking a black jellybean?

8. A card is drawn from a well-shuffled deck of 52 cards. What is the probability that the card is a heart?

9. A card is drawn from a well-shuffled deck of 52 cards. What are the odds of drawing a heart?

10. A card is drawn from a well-shuffled deck of 52 cards. What is the probability that the card is below a 9 (ace high)?

11. A card is drawn from a well-shuffled deck of 52 cards. What are the odds of a card below a 9 (ace high)?

12. A family has three children.  Using b to stand for boy and g to stand for girl, and using ordered triples such as(bbg) give: the sample space

13. A family has three children.  Using b to stand for boy and g to stand for girl, and using ordered triples such as(b, b, g) give: the event E that the family has exactly two daughters

14. A family has three children.  Using b to stand for boy and g to stand for girl, and using ordered triples such as(b, b, g) give: the event F that the family has at least two daughters

15. A family has three children.  Using b to stand for boy and g to stand for girl, and using ordered triples such as(b, b, g) give: the event G that the family has three daughters

16. Vocabulary • dominant • recessive • Punnett square • codominant

17. Mendel found that snapdragons have no color dominance; a snapdragon with one red gene and one white gene will have pink flowers.  If a pure-red snapdragon is crossed with a pure-white snapdragon, find the probability of the following. • a red offspring • a white offspring • a pink offspring

18. If carrier-detection tests show that two prospective parents have sickle cell trait (and are therefore carriers), find the probability of each of the following • their child would have sickle cell anemia. • their child would have sickle cell trait. • their child would be healthy (free of symptoms).

19. Tay-Sachs disease is a recessive disease. If carrier-detection tests show that one prospective parent is a carrier of Tay-Sachs and the other has no Tay-Sachs gene, find the probability of each of the following. • their child would have the disease. • their child would be a carrier. • their child would be healthy (free of symptoms)