In: Statistics and Probability
Refer to the following scenario for questions 12-16.
20% of a population of women have low bone density (osteopenia). A physician group has 400 women drawn from this population. They go through all the women and record the count of how many have low bone density. Let the random variable X represent the count of women with low bone density.
12) What is the approximate distribution of X?
Group of answer choices
1.Binomial, with n=400, and p=.20
2.Normal, with a mean of 400 and a standard deviation of 80
3.Normal, with a mean of 80 and a standard deviation of 8
4.Binomial, with n=.20 and p=400
13) Use the approximate distribution for X to find the probability that X lies between 68 and 77. Round your answer to two decimal places.
14) Use the approximate distribution for X to find the probability that X ends up being exactly 73. Round your answer to two decimal places.
15) Explain why the approximate distribution for X was safe to use to find the probabilities above.
16) Suppose that 99% of the population of women had low bone density instead of 20%. Would the approximate distribution of X still be safe to use? Explain why or why not.