Stats 1045 HW 16
According to genetic theory, there is very close to an even chance that both children in a two-child family will be of the same sex. Here are two possibilities. (i) 15 couples have two children each. In 10 or more of these families, it will turn out that both children are of the same sex. (ii) 30 couples have two children each. In 20 or more of these families, it will turn out that both children are of the same sex. Which possibility is more likely, and why?
(i), fewer couples gives a larger chance error.
Two hundred draws will be made at random with replacement from a box with the following tickets. -3 -2 -1 0 1 2 3 If the sum of the 200 numbers drawn is -20, what is their average?
-0.1
A die will be rolled some number of times, and you win $1 if it shows an ace (one) more than 20% of the time. Which is better: 60 rolls, or 600 rolls? Explain.
60 rolls because you need a larger chance error.
A die will be rolled some number of times, and you win $1 if it shows an ace (one) is exactly 16.67% of the time. Which is better: 60 rolls, or 600 rolls? Explain.
60 rolls because you need a smaller chance error.
A box contains 10,000 tickets: 4,000 0's and 6,000 1's. And 10,000 draws will be made at random with replacement from this box. Which of the following best describes the situation, and why?
The number of 1's is likely different from 6,000, but the difference is likely to be small compared to 10,000.
A gambler loses ten times running at roulette. He decides to continue playing because he is due for a win, by the law of averages. A bystander advises him to quit, on the grounds that his luck is cold. Who is right? Or are both of them wrong?
They are both wrong, the law of averages and luck have nothing to do with it- his chances are the same each time.
Two hundred draws will be made at random with replacement from a box with the following tickets. -3 -2 -1 0 1 2 3 In general, how can you figure out the average of the 200 draws, if you are told their sum?
sum ÷ 200
