Confidence Interval Estimation of Mean
(Sections 7.1-2)
Case 1 ( Known): Section 7.1
Parameter: (Unknown, fixed value)
Estimator:
X
(observed from a random sample of population)
Sampling Distribution:
From Z-table, we know:
X ~ N ,
n
P Z / 2
X Za/2
Price of house
Size of house in square feet
Presence (pool=1) or absence (pool=0) of pool
price
73900
89000
94000
135900
162900
119900
159900
179000
249900
325000
Average Price
111140
206740
sqft
1248
1400
1756
2400
2700
1875
1900
2300
2500
3800
pool
0
0
1
MAR 5621: Advanced Managerial Statistics:
Final Exam Solutions
Please make sure that your answers are legible and understandable. Show your work. There are 50 points total;
each part is worth 2 points unless otherwise noted. Good luck!
I. Cafeteria Coff
F Table: 5% Critical values (That is, 5% of the F distribution with the given df is to the right of these critical values.) Numerator degrees of freedom Denominator df 1 2 3 4 5 6 7 8 9 10 15 20 30 60 120 Infinity 1 161.45 199.50 215.71 224.58 230.16 233.
(The next 8 questions are based on the following information.)
The general manager of a supermarket chain believes that sales of a product are related to the amount of
space the product is given on shelves. Across a sample of stores, she measures the sale
DV:
IVs:
Page Costs for a 1-page ad
Audience (measured in thousands),
Male (percentage of audience that is male),
Income (median household income of audience)
1 predictor: Audience only
predicted PageCosts = 44,951 + 3.54 Audience
R2 = 0.7609
Adjusted R2
Introduction (Section 1.1)
This course applies and extends methods from STA 2023 to business
applications. We begin with a series of definitions and descriptions:
Descriptive Statistics: Methods used to describe a
measurements, typically either numericall
One-Way Analysis of Variance (Section 10.1)
Populations: c Groups, with mean j and variance j2 for population j
(j=1,.,c)
Samples:
, variance Sj2, for
c samples of size n j with mean
X
j
sample j (j=1,.,c)
Notation:
Xij the ith element from group j
subscr
Chi-Squared Test for Contingency Tables (Section
11.1-2)
Goal: Test whether the population proportions differ among k
populations or treatments (This method actually tests whether
the two variables are independent).
Data: A cross-classification table of c
NumericalDescriptiveMeasures(Chapter3)
MeasuresofCentralLocation(Sections3.1,3.3)
Arithmetic Mean: The sum of all measurements, divided by the number of
measurements.Onlyappropriateforintervalscaledata.
PopulationMean(Nitemsinpopulation,withvaluesX1,XN):
BasicProbability(Chapter4)
Approaches to assigning probabilities to outcomes
Classical Approach: Based on mathematical means of determining all outcomes of
an experiment, and assigning probabilities based on counting rules. We will not
pursue this approac
GraphicalDescriptiveMethods(Chapter2)
SingleVariable(Univariate)Graphs:
IntervalScaleOutcomes:
Histograms separate individual outcomes into bins of equal width (where
extremebinsmayrepresentallindividualsbeloworaboveacertainlevel).The
binsaretypicallylabe
Random Variables and Discrete Probability
Distributions
Chapter 5
Random Variable: Function or rule that assigns a number to each
possible outcome of an experiment.
Discrete Random Variable: Random variable that can take on only a
finite or countably infi
Comparing 2 Populations Chapter 9
We often wish to compare two groups with respect to either interval
scale or nominal outcomes. Typical research questions may include:
Does a new drug decrease blood pressure more than a currently
prescribed medication?
Estimated
Conditional
X0 (Specific value mean of Y for Standard error
of X)
X=X0
of Cond Mean
SUMMARY OUTPUT
10
9
0.501
1.289
Confidence
interval for cond Prediction interval
for 1 New Obs
mean when
when X=X0
X=X0
Note: For formulas to
work, upper left ha
MAR 5621: Advanced Managerial Statistics Assignment #2 (due in class Thursday, April 15, 2004)
This assignment may be done either individually or in teams of 2 people. (Teams should turn in only one paper, with both members' names on it.) When reporting n
MAR 5621: Advanced Managerial Statistics
Assignment #2 Solutions
Grading: Unless otherwise stated, all problems are worth 2 points per letter.
1. The following questions deal with the Magazine data we encountered in Assignment 1 and in
class.
DV: Page Cos
Practice Problems on Correlation & Simple Regression
1. Suppose that, across a sample of stores, the correlation coefficient between beer prices and beer sales is -0.65. What does this number indicate? (a) (b) (c) (d) There is almost no variability in bee
Practice Problems on Correlation & Simple Regression
1. Suppose that, across a sample of stores, the correlation coefficient between beer prices and beer
sales is -0.65. What does this number indicate?
(a)
(b)
(c)
(d)
There is almost no variability in bee
(The next 4 questions are based on the following information.)
In this problem we consider an analysis of the number of active physicians in a city as a function of the
city's population and the region of the United States that the city is in. The sample
(The next 4 questions are based on the following information.)
In this problem we consider an analysis of the number of active physicians in a city as a function of the
city's population and the region of the United States that the city is in. The sample
Questions on Multiple Regression
(The next 5 questions are based on the following information.)
Imagine that you are head of personnel at Huge Corp. The CEO keeps getting other people's mail by
mistake, so she asks you to conduct a study of mailroom produ