1. Quiz Tomorrow! Warm-Up… Quickwrite…
If your eyesight became severely bad, would you get stronger glasses/contact lenses or LASIK surgery? Why?
Ex: “If my eyesight became severely worse, I would choose _________ because ________________________________________________.”

2. Compare and Explain… your Warm-Up starting with Student #1 (1 min)
0.639
Not really.

3. Round Robin…
starting with the student who sits closest to the board at your table (1 min)
If your eyesight became severely bad, would you get stronger glasses/contact lenses or LASIK surgery? Why?
Ex: “If my eyesight became severely worse, I would choose _________ because ________________________________________________.”

4. Homework Answers 11. a) 0.082 b) 0.918 12. a) 0.028 b) 0.972 13.
b) Yes!

5. Probabilities for a binomial experiment

6. Probability of a Range of Successes
In such cases, we need to use the addition rule for mutually exclusive events
Ex: For n = 6 and p = 0.50,
P(4 or fewer successes) = P (r  4)
= P (r = 4 or 3 or 2 or 1 or 0)
= P(4) + P(3) + P(2) + P(1) + P(0)

7. Is there another way? Notice that P(4) = 0.234
Excerpt from Table 3 of Appendix II for n = 6

8. For n = 6 and p = 0.50, P (r  4) = P(4) + P(3) + P(2) + P(1) + P(0)
= = 0.890
We can also use the fact that the total of all P (r) values for r between 0 and 6 is 1 and the complement rule
Since the complement of the event r  4 is the event r  5,
P (r  4) = 1 – P(5) – P(6)
= 1 – – 0.016
= 0.890

9. Example: Hybrid Tomato
It is known that the seeds of a hybrid tomato have probability of germinating, and a biologist plants six seeds
What is the probability that exactly four seeds will germinate?
This is a binomial experiment with n = 6 trials: each seed planted represents an independent trial
We’ll say germination is success, so the probability for success on each trial is 0.70

10. n = 6 p = q = r = 4
P(4) = 0.324
Excerpt from Table 3 of Appendix II for n = 6

11. Example
What is the probability that at least four seeds will germinate?
In this case, we are interested in the probability of four or more seeds germinating
This means we are to compute P (r  4)
The events are mutually exclusive, so we can use the addition rule
P (r  4) = P (r = 4 or r = 5 or r = 6)
= P(4) + P(5) + P(6)
We already know the value of P(4), so we find P(5) and P(6)

12. Example
P(5) = and P(6) = 0.118
Now we have all the parts necessary to compute P (r  4).
P (r  4) = P(4) + P(5) + P(6) =
= 0.745

14. Homework