Introduction to Quantitative Methods for Economics
STATISTICS 104

Spring 2013
2.4 notes
Units of the range are the same as your data
#134 the spread is always equal to zero
#139 MAD0 mean absolute deviation, same units as your data
#143 Standard deviation is skewed by outliers. MAD and IQR make more sense logically
(theyre closer t
Introduction to Quantitative Methods for Economics
STATISTICS 104

Spring 2013
2.1 notes
Prediction in the subject line, win Starbucks card
How many students? (104+107) ~700 by5pm
Summarizing data
The average person lives in China; in 10 years India.
Average age 28
SAS used in commerce
SPSS used in psych
JMP dumbdown version of
Introduction to Quantitative Methods for Economics
STATISTICS 104

Spring 2013
Lecture 5
Correlation and Covariance
tell you if 2 variables are correlated
covariance gives you direction (+/)
Correlation gives you both direction and strength
Covariance and correlation
: measures of linear association
Sxy is the measure of variation
Introduction to Quantitative Methods for Economics
STATISTICS 104

Spring 2013
2.1 notes
Prediction in the subject line, win Starbucks card
How many students? (104+107) ~700 by5pm
Summarizing data
The average person lives in China; in 10 years India.
Average age 28
SAS used in commerce
SPSS used in psych
JMP dumbdown version of
Introduction to Quantitative Methods for Economics
STATISTICS 104

Spring 2013
1.30 notes
Part of the course: Summarizing the past, gather all the data
And then ask: what do you do with it? Prediction is the key.
[p2]
N population size
n Sample size
N>n (sample size is much less than the population)
Inferential stat relating samp