Prob & Stats Homework: Pregnancy Test, Distributions, Lottery, Hypothesis Testing - Prof. , Assignments of Statistics

Download Prob & Stats Homework: Pregnancy Test, Distributions, Lottery, Hypothesis Testing - Prof. and more Assignments Statistics in PDF only on Docsity! Math 13 Graded Homework #2 Due: 03/04/09 Show your work where possible. If you use a calculator or StatDisk, describe the process in lieu of showing the calculations. Be sure to staple all the pages together and put your name on each page. Each problem is worth the points stated with the total adjusted to 100 points. Prominently and clearly mark each answer. Remember, neatness counts! 1. (Ch 4) (15 points) Consider the table below of pregnancy kit test results: Positive Test Result (Pregnancy indicated) Negative Test Result (Pregnancy not indicated) Subject is pregnant 79 5 Subject is not pregnant 3 12 a. If one subject is randomly selected, find the probability that the subject is pregnant. b. If one subject is randomly selected, find the probability that the subject is not pregnant. c. If three different subjects are randomly selected from the 99 tested, find the probability that they all tested negative. d. If one subject is randomly selected, find the probability that the subject is pregnant or had a positive test result. e. If two different subjects are chosen, find the probability that either both are pregnant or both tested pregnant. 2. (5-2) (5 points) Let the random variable x represent the number of girls in a family of five children. Construct a table describing the probability distribution (Hint: List the different possible outcomes), and then find the mean and standard deviation. 3. (5-2) (8 points) In New Jersey’s Pick 4 lottery game, you pay $0.50 to select a sequence of four digits, such as 7273. If you win by selecting the same sequence of four digits that are drawn, you collect $2788. a. How many different selections are possible? b. What is the probability of winning? c. If you win, what is your net profit? d. Find the expected value. 4. (5-3) (9 points) In a clinical test of the drug Viagra, it was found that 4% of those in a placebo group experienced headaches. a. Assuming that the same 4% rate applies to those taking Viagra, find the probability that among eight Viagra users, three experience headaches. b. Assuming that the same 4% rate applies to those taking Viagra, find the probability that among eight randomly selected users of Viagra, all eight experienced a headache? c. If all eight Viagra users were to experience a headache, would it appear that the headache rate for Viagra users is different from the 4% rate for those in the placebo group? Explain.