STAT 200
Section 6388
Spring 2015
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Quiz #2 Please answer all 6 big questions. The maximum score for each question is posted at the beginning of the question, and the maximum score for the quiz is 100 points. Make sure your answers are as complete as possible and show your work/argument. In particular, when there are calculations involved, you should show how you come up with your answers with necessary tables, if applicable. Answers that come straight from program software packages will not be accepted. The quiz is due by midnight, coming Sunday.
IMPORTANT: You are requested to include a brief note at the beginning of your submitted quiz, confirming that your work is your own. The note should say, "I have completed this
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(c) (5 points) Suppose that the committee should have one President which has to be a female and two ordinary members who must be males.
How many different committees are possible?
4. X is normally distributed with mean 12 and standard deviation 4.
(a) (5 points)Find the probability that X will be more than 10.
(b) (5 points) Find the probability that X will be less than 13.5
(c) (6 points) Find the probability that X will be between 10 and 14.5
(d) (7 points) Find a such that P(X<a)=.85
(e)(7 points) Find b such that P(X> b)=.25
5. (7 points) Which of the following is not a binomial distribution and why? Justify your answer.
1. Tossing a fair quarter 10 times and looking at number of heads that shows up.
2. Rolling a fair die 10 times and looking at the number of times we get six dots showing up.
3. Rolling a fair die 10 times and keeping track of the numbers that are rolled.
4. Rolling 10 fair dice and looking at the number of dice that have 4 dots facing up.
6. Among companies doing highway or bridge construction, 80% test employees for substance abuse (based on data from the Construction Financial Management Association) A study involves the random selection of 12 such companies.
(a) (3 points) Find the probability that exactly 7 of the 12 companies test for substance abuse.
(b) (3 points) Find the probability that at least half of the companies test for substance abuse.
(c) (7 points)
d. The normal distribution may be a useful approximation, but it can’t exactly be the correct distribution. Explain why this is so.
Compute the probability of a stock-out for the order quantities suggested by members of the management team.
Donnelly begins his presentation with a thought experiment involving the tossing of a coin and predicts the possibility of a certain series of results. When predicting the possibility of heads, tails, heads (HTH) or heads, tails, tails (HTT), I, like most of the audience, believed that the chance of either possibility was equal. However, I did not take into account the possibility of overlap and how HTH was more like to be achieved in an overlap. I also did not catch that the HTH could appear in clumps because of the overlapping (the third "H" in HTH is also the first "H" in the next HTH). There was also the
The lottery is one of the oldest known game of chance, dating all the way back to 205 B.C. in the Han Dynasty. Being built upon pure luck, it has garnered attention all over the world in it's various forms of existence. After money began its association with the lottery in l443, it became even more popular worldwide. While existing in multiple forms, the most popular form of lottery is the randomly selected number method, where winnings are based on the correct numbers predicted. It is estimated that nearly half of the citizens living in the United States have participated in the lettery. An alarmingly high number ef the participants have admitted to lottery as their only chance ef being financially secure. what exactly are the edde of winnieg the Lottery? new is the probability te win increased? ?his mathematical inveetigatien hepes to shed light on these queries.
43.a) When a coin is tossed 4 times there are 16 possible outcomes and one way to roll a heads 4 times in a row. Let A represent the probability of rolling 4 heads.
Then complete the following distribution tables. Please pay attention to whether you should present the results in terms of percentages or simple counts.
| 2. Solve by simulating the problem. You have a 5-question multiple-choice test. Each question has four choices. You don’t know any of the answers. What is the experimental probability that you will guess exactly three out of five questions correctly? Type your answer below using complete sentences.
He retired to his bunk and, as a mathematical exercise, calculated the odds against his feat on the back of a laundry slip. His chances of doing it, he found, were one in almost ten million! Bewildered, he borrowed a pair of dice from the man in the bunk next to his. He tried to roll sevens again, but got only the usual assortment of numbers. He lay back for a moment, then resumed his toying with the dice. He rolled ten more sevens in a row.
B. “The Lottery”: There are two main parts in the Lottery I want to point out.
Example: Patrick flipped a number cube 40 times. A 5 appeared 10 times. The experimental probability of rolling a 5 is 10 out of 40 or 25%
12. The managers of a brokerage firm are interested in finding out if the number of clients a broker brings into the firm affects the sales generated by the broker. They sampled 12 brokers and determined the number of new clients they have enrolled in their lat year and their sales amount in thousands of dollars.
a. Among all employees who travel less than the median (54%), find the 95% confidence interval for the proportion who stay with D&Y for at least 3 years.
2. You and a friend are in a disagreement over who gets the last piece of pizza. What is the best way to fairly decide who gets to eat it?
b) A researcher will be unable to observe differences in risk attitudes. If workers who tend to be
b. What is the probability of failing on the first 2 trials and passing on the