DSC 670-123 Summer 2013 - Homework 3
Due Saturday 7/27/2013
To allow you time to study for the Midterm Exam, this assignment is half as long as usual. Therefore,
it will count half as much as a usual homework assignment (50 pts. instead of 100 pts.).
**Point values below are tentative and subject to change.**
Please note the following rules for this assignment:
1) Graphing calculators (such as TI-73 or higher) may not be used on any portion of the assignment. Scientific and four-function calculators are allowed.
2) All graphs are to be created by hand. Other homework questions (including tables) can be done by hand or on the computer.
3) The answers to all questions or question parts that don't involve calculations/tables/graphs must be written in full sentences.
If you have any questions or misunderstandings about these rules, please let me know. Not following Rules 1 & 2 is a violation of the course syllabus and Adelphi's
Honor Code and policies on Academic Honesty.
Assigned Sa 7/20
Reading (to review today's class):
Read Sections 3.4-3.6 and Section 4.1a (p.141-top of 145) of the textbook.
Moodle Forum #2: Questions about Chapters 1-3 or Section 4.1a
[5 pts.] Create a post where you discuss a topic from Chapters 1-3 or Section 4.1a that you find difficult. Explain your understanding (or misunderstanding) of that topic.
[5 pts.] Respond to a classmate's post with a clarification and/or explanation of the topic that they found difficult. If you find any misconceptions of the topic in the post you are responding to, please correct and/or explain them in your response.
Required Exercises for Chapter 3:
[10 pts.] Page 120 Exercise 3.33bcd (Answers to part a: mean = 10.28, variance = 4.098, standard deviation = 2.024)
[HINT: YOUR ANSWERS TO PART B ARE TO BE BASED ON THE GIVEN DATA. THEY ARE NOT TO BE BASED ON THE CHEBYSHEV OR EMPIRICAL RULES.]
[Part d (not in textbook): Compare your findings with what would be expected on the basis of Chebyshev's Rule. Based on this, are you surprised at the results in (b)?]
[10 pts.] Exercise 3.79 (not in textbook): At Starbucks, a sample of n = 5 tables were observed and the following data were recorded:
X = Number of drinks ordered
1
1
2
3
3
Y = Number of food items ordered
0
1
1
2
3
a) Find the covariance.
b) Find the coefficient of correlation.
c) How strong is the relationship between X and Y?
Required Exercises for Chapter 4:
[10 pts.] Page 149 Exercises 4.5(a,b,d) & 4.7(c,d) - For each part, explain why you think your answer is correct in a full sentence.
[10 pts.] Lab Exercise 4: A survey of 1000 adults was done to answer the question "Do you enjoy shopping?" The results indicated that out of 400 males, 100 said yes and 300 said no. And, out of 600 females, 450 said yes and 150 said no.
a) Create a visualization (contigency table, decision tree, or Venn Diagram - whichever you prefer) of this data.
b) Are the events "a male answering yes" and "a female answering no" mutually exclusive? Explain why or why not.
c) Are the events "a male answering yes" and "a female answering no" collectively exhaustive? Explain why or why not.
Reading (to prepare for next class):
Study Chapters 1-3 & Section 4.1a for the Midterm Exam.
Read Chapters 4-5 of the textbook (omit Sec. 4.3).