Name _
Statistics Formulas (Levine et al.), Exam 2 & Final
Mean
x
x=
n
Quartiles
Q 1 rank = (n+1)
Q 2 (median) rank = (n+1)
Q 3 rank = (n+1)
Sample variance
(Population s 2 , s : n in denominator)
s2 =
( x - x )2
s=
n-1
Addition rule of probability
P(A o
STA2000 Additional Problems on Descriptive Statistical Measures
For the two variables below, compute the and interpret the descriptive statistics:
Mean, median, quartiles, variance, SD.
You can compare your conclusions to the ones you reached when
you gra
STA2000 Categorical Charts homework (Chap2)
(1) A software manufacturer surveyed a random sample of customers about the reasons they used
the company's software packages.
(a) Create a horizontal bar chart and a pie chart to illustrate their findings.
(b)
STA2000 Categorical Charts homework (Chap2)
(1) A software manufacturer surveyed a random sample of customers about the reasons they used
the company's software packages.
(a) Create a horizontal bar chart and a pie chart to illustrate their findings.
(b)
Measure
Purpose
Advantages
Disadvantages
Median
Middle value in the
sample when
ordered from
lowest to highest
Most common
response
Less sensitive to extreme
values than the mean, thus
more typical of the data
Not as useful as mean when
every value must c
Independent-samples t test: Do tutored students have higher test scores?
Tutoring
No tutoring
89
87
78
80
86
78
80
73
70
76
t-Test: Two-Sample Assuming Equal Variances
Tutoring
Mean
Variance
Observations
Pooled Variance
Hypothesized Mean Difference
df
t S
Baruch College, CUNY
STA 2000 Prof. A. Gourgey
Computing Descriptive Statistics in Excel 2007
The Data Analysis Add-in computes the mean, the median, mode, range, sample variance and
standard deviation of a column of numerical data. Since the Add-in does
Baruch College, CUNY
STA 2000 Prof. A. Gourgey
Pivottables in Excel 2007
Pivottable is an Excel procedure for organizing data. It is a highly useful procedure for many
purposes. Here is a description of how to use Pivottable to count the values of a varia
Product
Biagio's Suparossa
Celeste Pizza for One
Healthy Choice Regular
Healthy Choice Deluxe
Master Choice 4-cheese
Pizsoy Tofu Pizza
Stouffer's
Weight Watchers
Wolfgang Puck
Domino's Veggie
Domino's Pepperoni
Pizza Hut Pan Pizza
Pizza Hut Hand Tossed
Se
STA2000 Quantitative (Numerical) Charts homework (Chap2)
(1) The following data represent ATM fees paid by a sample of bank customers over the past month.
(a) Create a frequency table that follows the guidelines for creating classes.
ATM fees
0
3
5
10
10
Baruch College, CUNY
STA 2000 Prof. A. Gourgey
A Comparison of the Measures of Variation
Measure
Purpose
Range
Distance from lowest to Quick and easy
highest value
Interquartile
Range
Distance from Q1 to
Q3
Sample
Variance
Average squared
distance of each
Count of COURSES1
COURSES1
Total
1
64
2
4
4
2
5
1
(blank)
Grand Total
71
Count of MAJOR
MAJOR
Total
1
20
2
20
3
13
4
4
5
2
6
3
7
3
8
7
(blank)
Grand Total
72
Major
Frequency Percentage
Accounting
20
28%
Finance/Eco
20
28%
Marketing
13
18%
Management
4
6%
Baruch College, CUNY
STA 2000 Prof. A. Gourgey
Sampling in Statistics (Rev. 7-08)
Sampling is necessary in most statistical studies because it is impractical to study the entire
population:
it is too time-consuming to reach everyone;
it is too expensive
Baruch College, CUNY
STA2000 Prof. A. Gourgey
Bar Charts
http:/mchb.hrsa.gov/whusa_06/healthstatus/indicators/graphs/0314cH.htm
http:/mchb.hrsa.gov/whusa_06/popchar/graphs/0207wlfHos.htm
http:/flowingdata.com/2008/08/19/3-worthwhile-alternatives-to-the-pi
Baruch College, CUNY
STA2000 Prof. A. Gourgey
Sample Test Questions for Exam 2 & Final
Note: This is not a list of all possible question types; it is a cross-section of some of the types of
questions you can expect to see on Exam 2 and the final. In addit
Solutions to Chicken Soup Survey
4. Descriptive Statistics (you should show the original formula in statistical notation as well as these
numerical final answers, and include the units of the variable where appropriate)
Mean
Variance
Standard deviation
27
Baruch College
STA 2000 Prof. A. Gourgey
Tips for Explaining a Categorical Chart
Gallup, Steroids and Baseball: What makes this a good paragraph?
How have fans of professional baseball reacted to these claims of steroid abuse in the sport?
A CNN/USA Today
STA2000 Categorical Charts homework (Chap2)
(1) A software manufacturer surveyed a random sample of customers about the reasons they used
the company's software packages.
(a) Create a horizontal bar chart and a pie chart to illustrate their findings.
(b)
Baruch College, CUNY
STA 2000 Prof. A. Gourgey
Analyzing Quantitative Data: The Chicken Soup Survey
Consumer Reports (November 1993) surveyed a sample of brands of chicken soup on various
nutritional characteristics. Below are their data on calories from
Independent-samples t test: Do tutored students have higher test scores?
Tutoring
No tutoring
89
87
78
80
86
78
80
73
70
76
t-Test: Two-Sample Assuming Equal Variances
Tutoring
Mean
Variance
Observations
Pooled Variance
Hypothesized Mean Difference
df
t S
Baruch College, CUNY
STA 2000 Prof. A. Gourgey
Setting Up Tables, Charts, and Descriptive Statistics on Excel 2003
I. How Can I Set Up A Categorical Frequency Table from My Raw Data?
1. Enter your original data in columns that list all the individual resp
Baruch College, CUNY
STA2000 Prof. A. Gourgey
Creating Quantitative Tables and Charts
Frequency Table
A quantitative variable, in contrast to a categorical variable, doesnt have natural categories,
so we have to create them by grouping the numbers into cl
Baruch College, CUNY
STA 2000 Prof. A. Gourgey
Setting Up Charts in Excel 2007
Pie Chart
1.
Type in your frequency and percentage table. The categories should be in descending
order of percentage (unless the word order takes precedence).
2.
Highlight the
Baruch College
STA 2000 Prof. A. Gourgey
Interpreting Quantitative Charts
Interpreting a chart for a quantitative variable is different from interpreting a chart for a
categorical variable. A categorical variable has categories that stand apart. A quantit