A child is observing squirrels in the park and notices that some are black and some are gray. For the next five squirrels she sees, she counts X = the number of black squirrels. Suppose X is a binomial random variable with n = 5 and p = 0.50. What is the variance for the number of black squirrels she will see, V(X)?
a. 1.00
b. 1.12
c. 1.25
d. 2.50
Question 2
Random samples from two age groups of brides (200 brides under 18 years and 100 brides at least twenty years old) showed that 50 of brides in the under 18 group were divorced after 15 years, while 40 of brides in the 20 or older age group were divorced after 15 years. The difference between the two proportions is 0.10, with a standard error of 0.0604 . What is a 95 confidence interval for the difference between the population proportions of brides who are divorced within 15 years (brides under 18 - brides at least 20)?
a. (-0.018, 0.218)
b. (-0.123, 0.023)
c. (-0.040, 0.160)
d. None of the above
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