Ho= Null hypothesis
Ha= Alternative Hypothesis
Alpha- significance level
The probability of rejecting the
null hypothesis AKA the
probability of making a wrong
decision
P Value is the probability of
obtaining a result as, or more extreme
then, the result

Computer Assignment #2
IDS 270
Regression Assignment
Pretend you work at an investment firm
Your boss wants to test the investment strategy that if interest
rates go down he will invest heavily in stocks
Run a regression analysis to decide if you want

Practice Exam
1. What is the matter with the graph shown below? What is the name for such a
graph?
Distribution by Income
100
80
60
40
20
0
0 to 75,000
Over 75,000
2. What are the terms for the following situations
A telephone survey research company is n

H
Review Test Submission: Chapter 9 HW
Review Test Submission: Chapter 9 HW
User
Angel Tafoya
Course
IDS 270 Introduction to Business Statistics(31167) 2013 Fall
Test
Chapter 9 HW
Started
11/22/13 4:58 PM
Submitted
11/22/13 8:27 PM
Status
Completed
Score

Review Test Submission: Chapter5Quiz
H
Assignments
IDS
270
Business
Statistics
I
(31167)
2014
Fall
12/5/14, 10:29 PM
Quizzes
Review Test Submission: Chapter5Quiz
Review Test Submission: Chapter5Quiz
User
Gerardo Perez
Course
IDS 270 Business Statistics I

H
Review Test Submission: Chapter 7 Blackboard HW
Review Test Submission: Chapter 7 Blackboard HW
User
Angel Tafoya
Course
IDS 270 Introduction to Business Statistics(31167) 2013 Fall
Test
Chapter 7 Blackboard HW
Started
11/5/13 7:51 PM
Submitted
11/5/13

H
Review Test Submission: Chapter 2 Blackboard Homework
Review Test Submission: Chapter 2 Blackboard Homework
User
Angel Tafoya
Course
IDS 270 Introduction to Business Statistics(31167) 2013 Fall
Test
Chapter 2 Blackboard Homework
Started
9/18/13 2:02 PM

Chapter 6 HW Problems
6.1
Assume standard deviation of invoice
amount is $200
Sample 100 invoices
What will be standard deviation of xbar?
What does CLT say?
Name sigma, n, mu?
6.2 & 6.3
68-95-99.7 rule says that the probability is
about 0.95 that x

Name: _ Date: _
Use the following to answer questions 1-5:
Are avid readers more likely to wear glasses than those who read less frequently? 300 men in
the Korean Army were selected at random and characterized as to whether they wore glasses and
whether t

H
Review Test Submission: Chapter 1 Blackboard Homework
Review Test Submission: Chapter 1 Blackboard Homework
User
Angel Tafoya
Course
IDS 270 Introduction to Business Statistics(31167) 2013 Fall
Test
Chapter 1 Blackboard Homework
Started
9/5/13 11:01 PM

H
Review Test Submission: Chapter 3 Blackboard Homework
Review Test Submission: Chapter 3 Blackboard
Homework
User
Angel Tafoya
Course
IDS 270 Introduction to Business Statistics(31167) 2013 Fall
Test
Chapter 3 Blackboard Homework
Started
9/20/13 10:16 PM

H
Review Test Submission: Chapter 4 Blackboard Homework
Review Test Submission: Chapter 4 Blackboard
Homework
User
Angel Tafoya
Course
IDS 270 Introduction to Business Statistics(31167) 2013 Fall
Test
Chapter 4 Blackboard Homework
Started
9/25/13 2:11 PM

H
Review Test Submission: Ch 8 BB
Review Test Submission: Ch 8 BB
User
Angel Tafoya
Course
IDS 270 Introduction to Business Statistics(31167) 2013 Fall
Test
Ch 8 BB
Started
11/15/13 2:39 PM
Submitted
11/15/13 3:17 PM
Status
Completed
Score
65 out of 70 po

H
Review Test Submission: Chapter 7 Quiz
Review Test Submission: Chapter 7 Quiz
User
Angel Tafoya
Course
IDS 270 Introduction to Business Statistics(31167) 2013 Fall
Test
Chapter 7 Quiz
Started
11/7/13 8:43 PM
Submitted
11/7/13 9:12 PM
Status
Completed
Sc

H
Review Test Submission: Chapter 5 Blackboard Homework
Review Test Submission: Chapter 5 Blackboard
Homework
User
Angel Tafoya
Course
IDS 270 Introduction to Business Statistics(31167) 2013 Fall
Test
Chapter 5 Blackboard Homework
Started
10/2/13 2:04 PM

Name: _ Date: _
1. A 95% confidence interval for the mean of a population is computed from a random
sample and found to be 9 3. We may conclude
A) there is a 95% probability that is between 6 and 12.
B) there is a 95% probability that the true mean is 9 a

User
Sunny Patel
Submitted
11/23/12 7:12 PM
Name
Chapter 9 HW
Status
Completed
Score
30 out of 30 points
Instructions
Question 1
3 out of 3 points
Problem 9.9 as a chapter 8 problem.
The z-value for this problem was:
Answer
Selected Answer:
3.30
Correct A

.3 in 1st Edition; 5.3 in 2nd Edition. Telemarketing. The probability that a call
will reach a live person is 0.2. The calls are independent.
(a) A telemarketer places 5 calls. What is the probability that none of them
reaches a live person.
Selected
Ans

Question 1
0 out of 3 points
1.7 (1st part) The shape of the distribution is
Answer
Selected Answer:
Right tailed
Correct Answer:
Roughly symmetric with a high side outlier.
Question 2
3 out of 3 points
1.7 (second part). Very roughly, the center of the

Power Problem Example
Example 6.20 (1st Edition)
Dont know 2nd Edition (But it is
the major example in section 6.4)
The Facts
Some researchers wish to know if exercise
will increase bone density in women
They measure the change in bone density
after 25

IDS 270
Chapter 8
1
Review & Preview
In the last chapter we talked about how to do t-tests
and confidence intervals when the mean and standard
deviation of the population are unknown
All of these problems involved variables that were
quantitative they v

IDS 270
Chapter 9
1
Review & Preview
Where have we been?
We have covered how to perform significance tests and
confidence intervals for a proportion
For a single group
To compare two groups
Where are we going?
We will now talk about how to perform s

Hypothesis Tests
When To Look Where on Table A
2
Back to New & Old Exam Example
Recall the following example that I have
been using for the last couple of weeks
I have an old exam that has a population
distribution of scores that is N(100,25)
I am thin

Two-Sided Hypothesis Tests
2
Review
In one of the first examples I talked about
putting changes into a test in order to see if the
population average test score would INCREASE
In the manufacturing example we made
changes to the manufacturing process in

Chapter 7 To Chapter 8
Transition & Quick Review
2
Recall From Ch. 7 to Ch 8
Chapter 7
Variables are scalar
Chapter 8
Variable are proportions
In one group vs. another
Prefer Coke or Pepsi
Compute xbar (sample
statistic)
Use it to make inference
f

User
Sunny Patel
Submitted
11/5/12 2:46 AM
Name
Ch 8 BB
Status
Completed
Score
70 out of 70 points
Instructions
Question 1
4 out of 4 points
8.8 (a) Find the Wilson Estimate
Answer
Selected Answer:
.19
Correct Answer:
.19
Question 2
6 out of 6 points
8.8

1
Additional Review Problems
2
Describe These Distributions
Hint: For A, where is the tail on the dog?
3
Repeat Problem 2
Suppose the weights of all the students in my
elective class are 165, 120, 195, 150, 129, 105, 187,
201, 160 and 145.
I sample 4 of

Submitted
11/16/12 5:16 PM
Name
Computer Assignment 6 Quiz
Status
Completed
Score
60 out of 60 points
Instructions
Question 1
10 out of 10 points
If the sample size n is large enough, then which of the following statement is true?
Answer
Selected
Answer:

Question 1
10 out of 10 points
If the sample size n is large enough, then which of the following
statement is true?
Selected
Answer:
The sampling distribution will be approximately
normal regardless of the shape of the population
distribution.
Correct
Ans

User
Sunny Patel
Submitted
11/2/12 1:54 PM
Name
Computer Assignment 5 Quiz
Status
Completed
Score
50 out of 50 points
Instructions
Question 1
10 out of 10 points
In this exercise, for the main hypothesis test, Ha was
Answer
Selected Answer:
4. mu(males) n