Business Statistics, Fall 2008
1. The ages of people in a class (to the nearest year) are as follows:
Age
Number of students
18
14
19 20
120 200
21 22 23
200 90 30
24 25
10 2
32
1
What is true about the median age?
A) It must be 20.
B) It could be any num
36(70)-207: Homework Set 4
DUE: Friday, Sept. 25 at the beginning of the class
Please make sure you write full solutions that show your work.
Reading: Chapter 4 in book
Lecture notes
Hand-In Problems:
(1) Chapter 4 exercise 52 (p. 274)
(2) Chapter 4 exerc
Homework Set 5, SOLUTIONS
Statistics 36(70)-207
October 2, 2009
(1)
Consider the following lottery game: You bet a dollar on a number between 0 and 9 that you
pick at random. If you are correct, you win $4, and otherwise, you win nothing. Whats the
probab
36(70)-207: Homework Set 5
DUE: Friday, Oct 2 at the beginning of the class
Please make sure you write full solutions that show your work (step-by-step
calculations with brief explanations, for example assumption of independence,
use of Central Limit Theo
Homework Set 6, SOLUTIONS
Statistics 36(70)-207
October 14, 2009
(1) Chapter 5 exercise 74 (p. 349)
Let PP denote the event that a plant is most protable, and let CP denote the event that a
contract is the most protable. Take A and B as dened in the probl
36(70)-207: Homework Set 6
DUE: Wednesday, Oct 14 at the beginning of the class
Please make sure you write full solutions that show your work (step-by-step
calculations with brief explanations)
Reading: Chapters 5.2-5.4 + Lecture notes
Hand-In Problems:
(
Homework Set 7, SOLUTIONS
Statistics 36(70)-207
October 23, 2009
(1) Chapter 6 exercise 18 (p. 375)
The bottom row of Table D shows that the critical z-value z is 1.96. The problem states the
standard deviation = 90, the mean of the sample is $640, and th
Homework Set 8, SOLUTIONS
Statistics 36(70)-207
October 30, 2009
(1) Chapter 6 exercise 46 (p. 389)
Let sof tware denote the mean of all numbers produced by the software. We need to test the
null hypothesis H0 : sof tware = . To test H0 , we assume that H
Homework Set 9, SOLUTIONS
Statistics 36(70)-207
November 6, 2009
(1) Chapter 6 exercise 54 (p. 394)
(a) They have the null and alternative backwards. If is the average level of improvement, the
null hypothesis should be = 0 (that there is no improvement).
Homework Set 10, SOLUTIONS
Statistics 36(70)-207
November 6, 2009
(1) Here we show that the expectation of the sample mean is the mean of the population:
1
E (X ) = E (
n
n
i=1
1
Xi ) = E (
n
n
i=1
1
Xi ) =
n
n
i=1
1
E (Xi ) =
n
n
=
i=1
1
n =
n
Also, wit
36(70)-207: Homework Set 10
DUE: Monday, Nov 23 at the beginning of the class
Reading: Chapter 7 + Chapter 8.1 + Lecture notes
Hand-In Problems:
(1) Let X1 , X2 , . . . , Xn be independent and identically distributed random
variables with mean = E(Xi ) an
Homework Set 11, SOLUTIONS
Statistics 36(70)-207
December 4, 2009
(1) Chapter 8 exercise 68 (p. 522-523)
(a) Let pm denote the population proportion of males students employed, and let pw denote the
population proportion of female students employed. Consi
Homework Set 4, SOLUTIONS
Statistics 36(70)-207
September 25, 2009
(1) Chapter 4 exercise 52 (p. 274)
The expected value, or the mean, is given by
X = (1 0.25) + (2 0.32) + (3 0.17) + (4 0.15) + (5 0.07) + (6 0.03) + (7 0.01) = 2.6
The census value is gre
36(70)-207: Homework Set 3
DUE: Friday, Sept. 18 at the beginning of the class
Please make sure you write full solutions that show your work.
Reading: Sections 2.1-2.4 and 4.1-4.2 in book
Lecture notes
Hand-In Problems:
(1) Chapter 2 exercise 64 (p. 135)
Homework
Homework, due Sunday June 2
Q11: Consider the following quantitative variables:
X= 0, 1, 2, 3, 4, 5, 6
Y= 0.94, 2.09, 8.39, 8.27, 10.94, 15.93, 22.14
Produce a scatterplot. Calculate the correlation and interpret it.
Find the least-square regres
Summer 2013 - QUIZ 1 - Solutions
Directions:
This quiz is closed book, closed notes, and closed mouth. If you have any questions,
please see the instructor. You may use a calculator.
A sample of 8 salaries was taken of employees in a large company. The fo
36-201 - Summer 2013 - QUIZ 2 - Solutions
Name:
Directions:
This quiz is closed book, closed notes, and closed mouth. If you have any questions,
please see the instructor. You may use a calculator.
0
2
4
y
6
8
10
1. (15) The following scatterplot represen
36-207 - Summer 2013 - QUIZ 2 - Solutions
Name:
Directions:
This quiz is closed book, closed notes, and closed mouth. If you have any questions,
please see the instructor. You may use a calculator.
1. (20 pts) The following two-way table summarizes the nu
36-201 - Summer 2013 - QUIZ 3
Name:
Directions:
This quiz is closed book, closed notes, and closed mouth. If you have any questions,
please see the instructor. You may use a calculator.
1. (5 pts) In order to determine if smoking causes cancer, researcher
36-207 - Summer 2013 - QUIZ 3
Name:
Directions:
This quiz is closed book, closed notes, and closed mouth. If you have any questions,
please see the instructor. You may use a calculator.
1. (5 pts) In a randomized block design, a block contains
(a) Individ
36-201 - Summer 2013 - QUIZ 4
Directions:
If you have any questions, please see the instructor. One page of notes is permitted.
You may use a calculator.
1. (30) In the following situations, determine if events A and B are disjoint or
not and if they are
36-207 - Summer 2013 - QUIZ 4
Name:
Directions:
If you have any questions, please see the instructor. One page of notes is permitted.
You may use a calculator.
1. (30) In the following situations, determine if events A and B are disjoint or
not and if the
36-201 - Summer 2013 - QUIZ 5
SOLUTIONS
Directions:
If you have any questions, please see the instructor. One page of notes is permitted.
You may use a calculator.
1. (35) A company is studying the monthly stipends of taxi drivers in New York
City. They t
36-207 - Summer 2013 - QUIZ 5
SOLUTIONS
Directions:
If you have any questions, please see the instructor. One page of notes is permitted.
You may use a calculator.
1. (35) The number of freshmen at CMU Pittsburgh is a Normal random
variable with unknown m
Homework Set 1, SOLUTIONS
Statistics 36(70)-207
September 4, 2009
(1) 1.14, p. 22
a) See graph (a) below.
b) See graph (b) below.
c) The bar graph in part (b) is called a Pareto bar graph. The Pareto graph makes it easy
to identify the most important cate
36(70)-207: Homework Set 1
DUE: Friday, Sept. 4 at the beginning of the class
Reading: Chapters 1.1-1.2 + pp.50-54 in book
Lecture handouts
Chapter 1 Appendix (on Minitab)
Hand-In Problems:
(1) Chapter 1 exercise 14 (p. 22)
(2) Chapter 1 exercise 16 (pp.