Monday's HW

Tonight you should complete the problems identified in class on our powerpoint slides. I've provided the answers below--if you want full credit, just the answers won't cut it! You need to show work!

1. "O negative blood" We expect to examine 16.667 donors; P(first universal donors is one of first four people) = 0.21925

2. "Suppose 20 donors..." b. We can assume independence because 20 donors is less than 10% of all blood donors. c. Mean = 1.2, St. Dev = 1.06; d. P(2 or 3 universal donors) = .311

3. "Colorblind Males"

• On average, a person should expect to ask 12.5 people to find one colorlind male.
• P(no colorblind among first 4 men) = 0.7164
• P(first CB on 6th person) = .0527
• P(CB on 1st or 2nd or 3rd....or 9th or 10th) = .5656

4. Olympic archer

• P(first bull on 3rd shot) = 0.032
• P(at least one bull) = 0.999936
• P(first bull on 4th or 5th) = 0.00768
• P(exactly 4 bullseyes) = 0.24576
• P(at least 4 bullseyes) = 0.90112
• P(at most 4 bullseyes) = 0.34464

5. Can we use probability models...we'll discuss in class

6. "Left Handed people"

• P(first lefty is 5th) = 0.0745
• P(some lefties) = 0.502
• P(lefty is 2nd or 3rd) = 0.2115
• P(exactly 4 lefties) = 0.0012
• P(at least 3 lefties) = 0.0179
• P(no more than 2 lefties) = 0.982