Extra exam practice
A college newspaper interviews a psychologist about a proposed system for rating the teaching
ability of faculty members. The psychologist says, The evidence indicates that the correlation
between a faculty member's research productivi
STA 1380: Ch. 2 4 Practice Problems
Dont forget to also study the material from Chapter 1!
1. Your home town is giving out free raffle tickets for a variety of gift cards to Dicks
Sporting Goods. Out of the 500 tickets given out, 25 tickets will win a $2
y Analysis of IQ By X
Oneway Anova
Summary of Fit
Rsquare
0.078173
Adj Rsquare
0.038094
Root Mean Square Error
14.67606
Mean of Response
Observations (or Sum
Wgts)
100.6
25
t Test
2-1
Assuming equal variances
Difference
8.205 t Ratio
Std Err Dif
5.875 DF
utions
Difference
Summary Statistics
Mean
Std Dev
Std Err
Mean
Test Mean
-0.041667 Hypothesized
Value
0.2401073
Actual Estimate
0.069313
DF
Upper 95% 0.1108902 Std Dev
Mean
Lower
-0.194224
95% Mean
N
One-sided Confidence Interval
12
0
-0.0417
11
0.24011
t
STA 1380: Ch. 2 Practice Problems
1. (a) What value should A be in the table below for us to have a probability distribution?
X
0
1
2
3
f (x)
A
0.1
0.2
0.5
(b) Is this a discrete or a continuous distribution? Explain briefly.
(c) Find the CDF.
(d) What is
STA 1380: Ch. 3 Practice Problems
1. During the spring semester I walked to campus every day. Suppose the time it took
for me to walk from my house to my office on campus has a uniform distribution from
12 to 18 minutes.
(a) What does the random variable,
STA 1380: Ch. 4 Practice Problems
Note: There may be a chapter 3 problem in here somewhere.
1. Suppose the number of coffee beans needed to make a cup of coffee at the nearest
Starbucks is normally distributed with a mean of 68 beans and a standard devia
STA 1380: Ch. 5 7 Practice Problems
1. Researchers are interested in the impact hypnosis has on motivation to do class work
for high school seniors (some of whom may be experiencing senioritis). The average
number of hours spent on class work per week by
STA 1380: Ch. 6 Practice Problems
Unless otherwise specified, use a 5% significance level.
For any hypothesis testing problem where you reject H0 , find an appropriate confidence
interval for the parameter of interest (the step 9 that we discussed).
1.
STA 1380: Ch. 7 Practice Problems
Unless otherwise specified, use a 5% significance level.
All JMP output is included with the solutions.
1. Does drinking caffeine really improve your focus to start a day more than just drinking
water? To test this, you
STA 1380: Ch. 8 Practice Problems
Unless otherwise specified, use a 5% significance level.
1. In an attempt to boost sales, a local clothing store performs a study to examine the
impact of different music types on how long customers spend in the store. T
STA 1380: Ch. 9 Practice Problems
Note: The JMP output can be found at the end.
1. Is a high school seniors final GPA a good predictor of the students final college GPA?
To examine this relationship, a research group randomly selects 20 college graduates
STA 1380: Ch. 5 Practice Problems
1. A sample of Alzheimers patients were tested to assess the amount of time they spend
in stage IV sleep. It has been hypothesized that individuals suffering from Alzheimers
may spend less time per night in the deeper sta
Syllabus
Rafael Mendoza-Arriaga
Rafael Mendoza
Elementary Business Statistics Syllabus
McCombs
Syllabus Highlights
Your Instructor
Rafael Mendoza-Arriaga, Ph.D.
My last name is Mendoza-Arriaga, not just Arriaga
You can call me Rafa
O ce: GSB 5.157
O ce ho
Chapter 12 Sample Surveys
How do we gather data?
Surveys
Opinion polls
Interviews
Studies
Observational
Retrospective (past)
Prospective (future)
Experiments
Population
the entire group of individuals that we want information about
Census
a complete count
What is the Shape of the Distribution?
1.Does the histogram have a single, central hump or several separated bumps?
2.Is the histogram symmetric?
3.Do any unusual features stick out?
Humps and Bumps
1.Does the histogram have a single, central hump or seve
Chapter 4
Displaying Quantitative Data
Dealing With a Lot of Numbers
Summarizing the data will help us when we look at large sets of quantitative data.
Without summaries of the data, its hard to grasp what the data tell us.
The best thing to do is to make
Chapter 3
Displaying and Describing
Categorical Data
The Three Rules of Data Analysis
The three rules of data analysis wont be difficult to remember:
1.Make a picturethings may be revealed that are not obvious in the raw data. These will be things
to thin
Contingency Tables
A contingency table allows us to look at two categorical variables together.
It shows how individuals are distributed along each variable, contingent on the value of the other
variable.
Example: we can examine the class of ticket and wh
Chapter 2
Data
What Are Data?
Data can be numbers, record names, or other labels.
Not all data represented by numbers are numerical data (e.g., 1=male, 2=female).
Data are useless without their context
The Ws
To provide context we need the Ws
Who
What (an
Counts Count
When we count the cases in each category of a categorical variable, the counts are not the data, but
something we summarize about the data.
The category labels are the What, and
the individuals counted are the Who.
Counts Count (cont.)
When w
CH 4 Day 1: Describing Quantitative Data:
Histogram & Dot Plot
When discussing a distribution, be it a histogram, dot plot
or stem plot, the following items need to be addressed:
Center
Unusual features
Shape
Spread
&
Be
Specific!
Shape: Look for the foll
Homework 5:
13)
Thomas should spend his $48 on 5 nights of bowling ($40 spent on bowling) and 2 nights of
billiards ($8 spent in billiards). The total utility form 5 nights of bowling equals (56 + 48 +
40 + 32 + 24) = 200. The total utility from 2 nights
Portfolio with Same Expected Return as the Benchmark
2.2
We can generate other portfolios dierent than the Minimum TE portfolio that will give us the
same return as the Benchmark. However, since these portfolios will have higher TE than the
Minimum TE por
Denition: Active Return is the dierence between the portfolios return and the benchmark
portfolios return.
N
X
B
B
ARtj = tj tj =
!i ri,tj tj
i=1
where i = 1, ., N stands for the ith rm in your portfolio of N stocks.
Denition: Tracking Error is dened as t
Using StatTools
First make sure that StatTools is installed in your computer.
To define a dataset:
1. Place the cursor in one of the cells that are part of the data set.
2. Click on StatTools->Data Set Manager.
3. Choose a name for the dataset under Name
PRACTICE TEST 1
Computer processors that have higher clock speeds result in faster computers. Hence,
manufacturers like AMD price processors based on their clock speed. Usually the
processors that are produced in the same batch have different clock speeds
Experiments and Observational Studies
Observational studies:
Conducted by observing choices made and recording the results.
Choices are not assigned by the researcher.
Can be either retrospective (subjects are selected, then historical data are compiled)