4 Steps to good Data Analysis:
1) Stability: Is the data/problem increasing, decreasing, cycling or stable?
Time Series Chart
Control Charts (not taught in this class)
2) Shape: Does the data/problem have any unusual data points or outliers? Is the data
CHAPTER 3 HOMEWORK ANSWERS
Mean = 6 Median = 7 There is no mode.
Range = 7 Variance = 8.5
Interquartile range = 5.5
Standard deviation = 2.9 Coefficient of variation = (2.915/6)100% = 48.6%
Z scores: 0.343, -0.686, 1.029, 0
EXCEL HOMEWORK ASSIGNMENT I
United Arab Emirates
Other Western Europe
Other Middle East
Other Far East and Oceania
Other Eastern Europe and
Other Central and South America
Two Sample T-Test Practice Problems
Comparing Two Independent Samples:
Given a sample of size n1 = 40 from a population with a known standard deviation
of 1 = 20 and an average 1 = 72 and an independent sample of n2 = 50 from
another population with an
CHAPTER 14 HOMEWORK ANSWERS
Holding constant the effect of X2, for each increase of one unit in X1, the
response variable Y is estimated to increase an average of 2 units. Holding
constant the effect
Adjusted R Square
Circu mfe re nc e Lin e Fit Plot
Sum of Squared Difference of Residuals
Sum of Squared Residuals
OmniPower Sales Analysis
Price and all other X
- Excel Assignment 1
Central and South
Correlation vs. Regression
scatter plot = relationship b/w 2
measures relationship strength.
One input/ one output.
Do NOT know causation.
Regression analysis predicts
dependent variable from at least
CHAPTER 13 HOMEWORK ANSWERS
yes, (b) no, (c) no, (d) yes
SST = 40 and r2 = 0.90. So, 90% of the variation in the dependent variable
can be explained by the variation in the independent variable.
Chapter 13: Simple Linear Regression
CHAPTER 13 HANDOUT
NOT RESPONSIBLE FOR:
Calculating Confidence Intervals on mean value of Y give X
Calculating F test Statistic
T-test for Correlation Coeffiecient
Possible Exam Questions on the Regression Excel Output:
1) What is the Input and Output?
2) What is the Sample Size
3) What is the Regression Equation?
4) Does the line fit the data? Why or Why Not?
5) What is the R-squared value? Interpret R-Squared?
USA Today Snapshots from April 2007
What is the charts main point?
How does it relate to you?
What is one good feature of the
What is one bad feature of the chart?
Do you believe the chart? Why or
What is the charts main
How does it relate to you?
What is one good feature of
What is one bad feature of the
Do you believe the chart?
All 2010 & 2011 Graphs pulled from internet
CHAPTER 9 HOMEWORK ANSWERS
is the probability of making a Type I error that is, the probability of incorrectly
rejecting the null hypothesis when in reality the null hypothesis is true and should
not be rejected.
= 20 minutes. 20 minute
CHAPTER 1 HOMEWORK ANSWERS
Three sizes of soft drink are classified into distinct categoriessmall,
medium, and largein which order is implied.
numerical, discrete, ratio scale
numerical, continuous, ratio scale
CHAPTER 7 HOMEWORK ANSWERS
A simple random sample would be less practical for personal interviews because of travel costs (unless
interviewees are paid to attend a central interviewing location).
The four types of survey errors are: (a) c