Stat 200 midterm exam spring 2020 solutions

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(For Questions 1, 2, 3 and 4) There are 25 students enrolled in Stat 200 course. Their scores on Test one is written in following table 1.

1. (4 points) construct a frequency distribution on scores.

2. (4 points) Construct a relative frequency distribution test one scores repeated below:

scores

Frequency

50-59

60-69

70-79

80-89

90-99

3. (4 points) construct a histogram of the scores for the given frequency.

4. (4 points) Construct stem and leaf display for the scores in Table 1.

5. (4 points) A soda company wants to stimulate sales in this economic climate by giving customers a chance to win a small prize for every bottle of soda they buy. There is a 20% chance that a customer will find a picture of a dancing banana () at the bottom of the cap upon opening up a bottle of soda. The customer can then redeem that bottle cap with this picture for a small prize. Now, if I buy a 6-pack of soda, what is the probability that I will win something, i.e., at least win a single small prize?

6. (5 points) My brother wants to estimate the proportion of Canadians who own their house. What sample size should be obtained if he wants the estimate to be within 0.02 with 90% confidence if

a. he uses an estimate of 0.675 from the Canadian Census Bureau?
b. he does not use any prior estimates? But in solving this problem, you are actually using a form of “prior” estimate in the formula used. In this case, what is your “actual” prior estimate? Please explain.

7. (2 points) At men’s clothing store, 12 males bought green sweaters, 8 purchased blue golf sweaters, 4 bought white sweaters and 7 decided to by gray sweaters. If a customer is selected at random, calculate the probability that he bought:

(2 points)(a) Green sweater (b) blue sweater or white (c) blue or gray or white (d) A sweater which was not gray.

8. (2 points) (a) Given definition of Normal ( Gaussian distribution) by citing an example. Draw graph of the distribution.

(3 points) (b) Consider a normal distribution with a mean of 14 and variance of 26. What is the Z score for the value of 16?

Hint: Read from the text-book regarding Normal distribution and go over the power point lecture examples. Then work – out this exercise.

Important: Please read carefully……. You are allowed to use technology for the following Problems (Problem #9 and Problem #10). Most probably, you have to use technology or you may have to spend hours, to carry out the necessary calculations by hand. Nonetheless, you should clearly delineate and explain your logic and reasoning on how to tackle problems #9, and #10.

9. (8 points) The Undesirable Air Lines (UAL???) is notorious for its cost-cutting substandard customer service. Consequently, only 85% of the ticket holders will show up for a flight. The Air Lines workhorse, the Boring 878, has 234 seats. UAL, of course, will make extra money by overbooking. However, they have to worry about the FAA fines, and they have to keep a safety margin, say, that there is at least 95% probability that they can accommodate all those who show up for the Boring 878 flight. How many seats can they actually sell in this case?

10. (8 points) It is an open secret that airlines overbook flights, but I have just learned recently that bookstores underbook (I might have invented this new term.) textbooks……….

To make a long story short, our school designated virtual bookstore, MBS Direct, routinely, as a matter of business practice, orders less textbooks than the amount requested by our school’s Registrar’s Office. That is what I have figured out……. Simply put, MBS Direct has to “eat” the books if they are not sold. Do you want to eat the books? You may want to cook the books before you eat them! Oops, I hope there is no account major in this class?

OK, let us cut to the chase….. MBS Direct believes that only 85% of our registered students will stay registered in a class long enough to purchase the required textbook. Let’s pick on our STAT 200 students. According to the Registrar’s Office, we have 600 students enrolled in STAT 200 this fall 2019.

Suppose you are the CEO of MBS Direct, and you want to perform a probability analysis. What would be the number of STAT 200 textbook bundles you would order so that you stay below 5% probability of having to back-order from Pearson Custom Publishing? (Note: Our Provost would be very angry when she hears that textbook bundles have to be back-ordered. In any case, by next fall, we will no longer need the service of MBS Direct as we are moving 100% to free eResources. Auf Wiedersehen, MBS Direct……)

Continue to order Get a quote

July 1, 2023

Zoo project

INTRODUCTION: This assignment is designed to help you learn more about and

observe in real time some of the primates we have studied in our course, in this

case the chimpanzee. Besides your zoo visit, your final written report should

reflect thoughtful consideration of the assigned readings. The report will be based

on a description of the events in the chimp enclosure over period of 45 minutes

(minimum). Judge your time wisely and make sure to follow all the directions

presented below here. A total of 15 points may be earned IF you follow all

directions and present a well-prepared report (with ticket attached) by the

A. GRADING: Points will be awarded according to how your report covers the

following issues:

1. Describe enclosure and compare it to chimp natural habitat 3 points

2. Identify individual chimps as Adult Male-1; Adult Female-1; Juvenile Male-

1; Juvenile Female-1, etc. [If this is difficult, try another way to identify the

subject of your comments.] Describe at least one interaction/behavior, anything

from fast moving to just “lounging together” while grooming, etc. 5 points

3. Integrate key ideas from assigned readings* and clearly relate them to these

L.A. Zoo chimps. 5 points

4. Organize, proof read, and include a “mug shot” with admission ticket

2 points

TOTAL POINTS…15

* Required readings:

a. Review Ch. 7 (pp.167-68) and Ch. 8 (pp.180-89) for info on the primates,

in this case the chimpanzee

b. Read “The 2% Difference,” in ANNUAL EDITIONS: Physical

Anthropology 08/09 edition. See also in Discover Magazine, April 2006;

available on-line at http://discovermagazine.com/2006/apr/chimp-

genome.

ANNUAL EDITIONS (08/09)reference to the attendant. Make sure to read these selections before you go to the

Zoo.

B. KEEP IN MIND: When you walk up to any animal enclosure, the behavior

may appear to be erratic or random; maybe “nothing” is happening. However,

much of the behavior is patterned in response to a stimulus not necessarily evident

to us. Be patient. The best you can do is to carefully & accurately describe their

physical activity & note its context at the time. There is no magic bullet! Do your

best.

The Enclosure. If you include photos, do provide SHORT CAPTIONS. If you are

artistic, make a sketch of the enclosure and include it with your report. While there

is no ironclad page count for this project, please do not use pictures & drawings as

fillers! Your thoughts are paramount.

C. DRAFTING YOUR REPORT: After you have completed your observations,

go aside and carefully read over your notes. Are there any notable behavior

patterns, anything that indicates relationships, friendships, or pecking order? You

should draw on the physical characteristics of the chimpanzee provided in Ch. 8.

Integrate key information from the other required readings. Omit it and you will

lose points. Don't fret; a good faith effort is what counts here.

D. ORGANIZING YOUR REPORT: A good report will be well organized

around the “Grading” topics. About four to five pages (double spaced) is

acceptable. This does NOT include your cover page, any photos, charts or maps.

Use one-inch margins and avoid “padding” with empty spaces between sections or

paragraphs. Most of all, sincere work and a true learning experience is what we

are after here. Your instructor’s “eagle eye” can spot the proverbial fluff and “b.s.”

Do a good job and shine!