Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Spring 2014
Midterm exam2
Sample exam STATUB.0103
Instructor: Kevin Brabazon
Name:
Complete all questions. If you believe a question needs a hypothesis testing approach, do not use
a confidence interval instead of the hypothesis test. If you are using an advanced ca
Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Spring 2014
Russab Ali
STATUB.0103
Homework Set 1
The abbreviation MBS10 refers to the 10th ed of the course textbook. MBS11 refers to the
11th ed.
1. Consider this set of 6 values:
131, 124, 184, 119, 166, 154
Find the mean, median, and standard deviation for this
Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Spring 2014
C22.0103 Homework Set 3 Spring 2012
1. The file CDCLifeTable is available from the course web site. Its in the M folder;
the direct link is
http:/people.stern.nyu.edu/gsimon/statdata/B01.1305/M/index.htm
This has data for nonHispanic whites, with gender
Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Fall 2012
Sample Midterm 1 Solutions
STATUB.0103 Statistics for Business Control and Regression Models
1. (20 points) True/False. For each of the following, answer True or False ; an answer of True
is interpreted as always true.
(a) If the IQR (interquartile range
Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Spring 2014
1. The company's unadjusted trial balance includes the following account balances:
The following data are available to determine adjusting entries:
A) $4,350 of prepaid insurance expired during the period.
B) The company estimates depreciation expense of
Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Spring 2014
Final Paper for STATUB.0103
Instructor: Kevin Brabazon
This can be completed as a group [up to 4 members] or individual assignment.
This assignment requires you to analyze a data set using the statistical tools you have
learned during the semester. The d
Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Fall 2012
Sample Final
STATUB.0103 Statistics for Business Control and Regression Models
The nal is open book and open note. Your are also permitted use of a calculator. Multiple
choice problems (615) are worth 5 points each. It is possible to get partial credit f
Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Spring 2014
Russab Ali
STATUB.0001
Homework Set 2
Fall 2013
1. If one card is selected at random from a standard deck of 52, find the probability that
a.
the selected card is a diamond () ;
1/4
b.
the selected card is a seven;
1/13
c.
the selected card is red;
1/2
d
Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Spring 2014
Russab Ali
8 9:15 AM Professor Brabazon
HOMEWORK SET 4
STATUB.0103
1. If Z is a standard normal random variable, find the probability that
a.
0 Z 1.24
0.3925
b.
Z > 0.45
0.5 + 0.1736 = 0.6736
c.
 Z  0.80
Z 0.80 OR Z 0.80
Distance from 0 to 0.80 on ta
Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Fall 2012
Multiple Regression, F Tests Solutions
STATUB.0103 Statistics for Business Control and Regression Models
Multiple Regression
1. We used n = 43 data points to t a multiple regression model to explain email usage in terms
of the variables Social, Text, and
Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Fall 2012
Forecasting, Multiple Regression Solutions
STATUB.0103 Statistics for Business Control and Regression Models
Inuential Points (Review)
1. Should an outlier or a point with high leverage always be removed from a regression analysis?
Solution: No. It shoul
Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Fall 2012
Regression with Qualitative and Quantitative Variables Solutions
STATUB.0103 Statistics for Business Control and Regression Models
Multiple Regression with Qualitative Predictors (Review)
1. We asked 46 NYU students how much time they spend on social med
Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Fall 2012
Residuals, ANOVA, and Model Assumptions Solutions
STATUB.0103 Statistics for Business Control and Regression Models
Least Squares Regression (Review)
1000 1200 1400
q
q
q
q
q
800
price
1. Here is a scatterplot of the sizes (in 100 ft2 ) and prices (in $1
Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Spring 2014
Additional practice problems
1.
1
Given
the
followin
g
complet
e list of
balances
, what
will be
the total
credits
in the
trial
balance,
assumin
g no errors exist in the accounts?
1. Retained Earnings
$28,000
2. Merchandise Inventory
9,000
3. Accumulated
Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Spring 2014
we sold
34.3 billion cups
just in 2017
that means
$34.3 billion
in revenue
5cups soldmNY daily
1+ in illion
25.6% cheaper
than our leading competitors
thats a difference of a
$0.998: SternIceCreams average price
$1.254: Competitors average price
per cup!
Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Spring 2014
SYLLABUS FOR STAT.UB.0103.02
STERN SCHOOL OF BUSINESS
NEW YORK UNIVERSITY
Course objectives:
The mission of this course is the achievement of an understanding of the nature of data and of
randomness in business situations. Objectives include the control o
Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Fall 2012
Regression Model Assumptions and Inference Solutions
STATUB.0103 Statistics for Business Control and Regression Models
Least Squares Fit and ANOVA Table (Review)
1000 1200 1400
q
q
q
q
q
800
price
1. Here is a scatterplot of the sizes (in 100 ft2 ) and p
Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Fall 2012
Regression Diagnostics Solutions
STATUB.0103 Statistics for Business Control and Regression Models
Inference for Regression Parameters (Review)
1. Here are the least squares estimates from the t to model
Price = 0 + 1 Size + ,
where price is measured in
Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Fall 2012
Introduction to Condence Intervals Solutions
STATUB.0103 Statistics for Business Control and Regression Models
Sampling Distributions and the Central Limit Theorem (Review)
1. You run a restaurant on St. Marks Place. Some proportion of diners at your res
Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Fall 2012
Condence Intervals Solutions
STATUB.0103 Statistics for Business Control and Regression Models
Population Mean (Known Variance)
1. A random sample of n measurements was selected from a population with unknown mean
and known standard deviation . Calculat
Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Fall 2012
More Condence Intervals Solutions
STATUB.0103 Statistics for Business Control and Regression Models
Population Mean (Unknown Variance)
1. In the class survey of 51 people, the mean number of time per week spent using social media
was 290 minutes, and the
Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Fall 2012
Continuous Random Variables Solutions
STATUB.0103 Statistics for Business Control and Regression Models
Uniform random variables
1. Suppose X is a uniform random variable on the interval [0, 360).
(a) What is P (0 < X < 180)?
Solution:
P (0 < X < 180) =
Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Fall 2012
Discrete Random Variables Solutions
STATUB.0103 Statistics for Business Control and Regression Models
Discrete random variables
1. Suppose you ip two coins. Let X be the random variable which counts the number of heads
on the two tosses. List all of the
Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Fall 2012
Hypothesis Tests Solutions
STATUB.0103 Statistics for Business Control and Regression Models
Null and alternative hypotheses
1. General Mills claims that there are 16 ounces of cereal in the average box that they manufacture.
As a consumer advocate, you
Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Fall 2012
Hypothesis Tests 2 Solutions
STATUB.0103 Statistics for Business Control and Regression Models
Tests on the population mean (unknown variance)
1. The average nicotine content of a brand of cigarettes must be less than 0.5 mg for it to qualify
as a Low Ni
Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Fall 2012
Independence & Bayes Rule Solutions
STATUB.0103 Statistics for Business Control and Regression Models
The birthday problem
1. A class has 60 students. What is the probability that at least two students have the same
birthday?
Solution: Assume that everyo
Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Fall 2012
Normal Random Variables Solutions
STATUB.0103 Statistics for Business Control and Regression Models
Normal CDF
1. The dressed weights of Excelsior Chickens are approximately normally distributed with mean
3.20 pounds and standard deviation 0.40 pound. Ab
Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Fall 2012
Probability Review Problems Solutions
STATUB.0103 Statistics for Business Control and Regression Models
Homework problems
1. Five businesspeople meet at a convention. How many handshakes are exchanged if each shakes
hands with all the others?
Solution: T
Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Fall 2012
Sampling Distributions Solutions
STATUB.0103 Statistics for Business Control and Regression Models
1. Estimate the proportion of NYU undergraduates who own iPhones.
(a) What is the population?
Solution: The iPhone ownerships of all NYU undergraduates enr
Stats For Business Control Regression and Forecasting Models
STATUB 103.1.003

Fall 2012
Association, Correlation, and Causation Solutions
STATUB.0103 Statistics for Business Control and Regression Models
Association and Correlation
1. Let us consider a test of childrens ability to write French text correctly from dictation. For
simplicity w