uiz 2 Each question is worth 1 point. Don't leave anything blank. I can always find a way to give you some credit if you've made an attempt. Be sure to post any questions you have after the answers open. The work you turn in by 11:59 P.M. on Oct. 1st must be your own. 1. If 2 out of 100 second graders are randomly selected, find the probability that they are both boys and like spring: Boys Girls Spring 39 6 Summer 35 5 Fall 8 2 Winter 4 1 a) With replacement? b) Without replacement? 2. Assume adults have IQ scores that are normally distributed with a mean of 100 and a standard deviation of 15. a. Find the probability that a randomly selected adult has IQ < 115 b. Find the probability that a randomly selected adult has IQ > 70 c. Find P30, which is the IQ separating the bottom 30% from the top 70% 3. a. When would the mean grade in a class on a final exam be considered a statistic? b. When would it be considered a parameter? c. When you construct a 95% confidence interval, what are you 95% confident about? 4. My parents lived in Florida and wanted to know the probability of winning the Florida Fantasy 5 if they bought one ticket. They had to pick the five winning numbers from 140. Each randomly selected number is different and order doesn't matter. What is the Probability of their winning? 5. I randomly select samples of 9 participants from a population. I do this repeatedly. I calculate the mean of each of the samples and plot these means. If the population mean equals 12, and the population standard deviation is 6, what is the standard deviation of my distribution? 6. In a study of families with children with disabilities, group of 6 US households were randomly selected. In the table below, the random variable x represents the number of households among 6 that had a child with a disability living there. x 0 1 2 3 4 5 P(x) 0.02 0.15 0.29 0.26 0.16 0.12 a) Is this a probability distribution? b) What is the mean? c) What is the standard deviation? 7. Ten peas are generated from parents having the green/yellow pair of genes so there is a 75% probability that an individual pea will have a green pod. Find the probability that among the 10 offspring peas, at least 9 have green pods. 8. Find the critical value: a. Z0.02 b. Z0.01 c. Z0.10