Western University (Ontario)  Also known as University of Western Ontario
STATISTICS 2035

Fall 2013
Practice Questions Units 5 and 6 Chapter 6 and Chapter 7 (7.1 to 7.4)
1.
Approximately how many observations do we need to draw in a simple random sample so that the
width of a 90% confidence interval
Western University (Ontario)  Also known as University of Western Ontario
STATISTICS 2035

Spring 2016
What is Statistics?
Statistics is the science of collecting,
organizing, summarizing and interpreting
numerical facts, which we call data
Statistics start with a question
1.
What percent of students a
Western University (Ontario)  Also known as University of Western Ontario
STATISTICS 2035

Spring 2016
Other Graphical Displays
1. Frequency Polygon
same horizontal axis as histogram
constructed by marking a point at the
midpoint of each class
height of graph is equal to the
frequency of that class
Western University (Ontario)  Also known as University of Western Ontario
STATISTICS 2035

Spring 2016
Chapter 4 Probability
(The study of randomness)
Most statistical analysis begins by collecting
data
the best way to collect data is to set up an
experiment and observe the results
however, before yo
Western University (Ontario)  Also known as University of Western Ontario
STATISTICS 2035

Spring 2016
Measuring The Spread/Measures of
Variability (section 3.2)
Example
We are to compare four factories that are
producing 600ml bottles of water. We need
to determine which factory is doing the best
job
Western University (Ontario)  Also known as University of Western Ontario
STATISTICS 2035

Spring 2016
Chapter 3 Descriptive Statistics
In addition to graphing the data, we can gain
more insight by condensing the data into a
few single numbers which will summarize
the distribution in a clear and concis
Western University (Ontario)  Also known as University of Western Ontario
STATISTICS 2035

Spring 2016
Grouped Data (section 3.3)
(I) Weighted Means (not in textbook)
In calculating the mean of a population or
sample, we sum each measurement and
divide by the number of measurements
that is, each measu
Western University (Ontario)  Also known as University of Western Ontario
STATISTICS 2035

Spring 2016
(Skip Counting Rules (Section 4.3) for now)
Conditional Probability and Independent
Events (sections 4.6/4.7)
Sometimes probabilities need to be
reevaluated as additional information
becomes available
Western University (Ontario)  Also known as University of Western Ontario
STATISTICS 2035

Spring 2016
Bayes Rule (section 4.8)
Sometimes you need to determine posterior
probabilities based on your prior
probabilities
That is, you may want to determine P(AB)
given that you know P(A) and P(BA).
P(AB)
Western University (Ontario)  Also known as University of Western Ontario
STATISTICS 2035

Spring 2016
Chapter 5 Discrete Random Variables and
Probability Distributions
Definition
A random variable is a variable which
assigns a numerical value to every outcome
of a random experiment
There are two types
Western University (Ontario)  Also known as University of Western Ontario
Stats for Business and Social Science
STATISTICS 2035

Summer 2017
Comparing Two Population Proportions
(section 10.4)
We have:
population population
proportion
sample
size
count of
sample
successes proportion
1
p1
n1
x1
2
p2
n2
x2
x1
n1
x
p 2 = 2
n2
p 1 =
We are int
Western University (Ontario)  Also known as University of Western Ontario
Stats for Business and Social Science
STATISTICS 2035

Summer 2017
Counting The Possibilities (section 4.3)
1.
The mn counting rule
For an operation that can be done in mways
and a second operation that can be done in
nways, the operations can then occur, in
order,
Western University (Ontario)  Also known as University of Western Ontario
Stats for Business and Social Science
STATISTICS 2035

Summer 2017
Dependent Samples: Inference About the
Difference Between Two Population Means
MatchedPairs tTest (section 10.3)
We start off with a 2sample problem:
x1 = sample data from population 1
x2 = sample
Western University (Ontario)  Also known as University of Western Ontario
Stats for Business and Social Science
STATISTICS 2035

Summer 2017
Multiple Comparison Tests (section 11.3)
In ANOVA, if H0 is rejected, the test does
not give any information about which means
are different.
Further statistical analysis is needed to
determine which
Western University (Ontario)  Also known as University of Western Ontario
Stats for Business and Social Science
STATISTICS 2035

Summer 2017
What is Statistics?
Statistics is the science of collecting,
organizing, summarizing and interpreting
numerical facts, which we call data
Statistics start with a question
1.
What percent of students a
Western University (Ontario)  Also known as University of Western Ontario
STATISTICS 2035

Fall 2013
Stats 2035 Midterm #2 Booklet Solutions
A. Exponential
Example 1. Jobs are sent to a printer at an average of 3 jobs per hour.
y= # of jobs sent to the printer per hour y=0,1,2,.
~
3
x=time between
Western University (Ontario)  Also known as University of Western Ontario
STATISTICS 2035

Fall 2013
Practice Test on Chapters 4 and 5
Use the following information for the next TWO questions:
The number of hits on a website follows a Poisson distribution with an average rate of 3.3 per minute,
while
Western University (Ontario)  Also known as University of Western Ontario
STATISTICS 2035

Fall 2013
Units 7 and 8  Practice Problems Chapter 7 (7.5 to 7.8), Chapter 8, Chapter 9
1.
Mr. Chips produces potato chips and packages the chips in 200g bags. A consumer believes that the
bags may contain les
Western University (Ontario)  Also known as University of Western Ontario
STATISTICS 2035

Fall 2013
Solutions to Unit 78 Practice Test
1. Answer A
Type I error = P(reject Ho  Ho is true). Thus they are accusing Mr. Chips of
underfilling bags when in fact Mr Chips is filling the bags to the correct
Western University (Ontario)  Also known as University of Western Ontario
STATISTICS 2035

Fall 2013
Statistical Sciences 2035 201112
MID TERM EXAM #1
Friday, November 16, 2012
7:00 pm  9:00 pm
Read these instructions
1. This is a closed book examination. Calculators are permitted.
2. There are 30