Transcript Notes on Computer Printout for LSRL

Using Excell
*Bring Money for Yearbook!
Computer Software
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There are two statistical software packages
that are often used
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Minitab
JMP
Once you understand the statistical ideas,
you can read and work with almost any
software output.
DATA Analysis
(school computers)
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Go to File
Down to “Options”
Click on “Add ins”
Mark the first 2 – Data Pak
Click on “Go”
It will now be found under Data in the Data
Analysis section.
DATA Analysis (Windows 97)
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Go to Tools
Click on “Add ins”
Check 1st 2
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It will now be found under Tools
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DATA Analysis (Vista)
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Go to Tools
Click on “Add ins”
Check 1st 2
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It will now be found under Tools
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A study of nutrition in developing countries collected data from the
Egyptian village of Nahya. Here are the mean weights (in kg) for
170 infants in Nahya who were weighed each month during their
first year of life:
Age (mths)
Weight (kg)
1
4.3
Put independent variable in column A.
2
5.1
Put dependent variable in column B.
3
5.7
Go to Data Analysis – to Regression
4
6.3
5
6.8
6
7.1
Hightlight A column for x-range
7
7.2
Click on labels (if you included them)
8
7.2
Click on output – click space to put it
9
7.2
10
7.2
11
7.5
12
7.8
Hightlight B column for y-range.
If you want the normal probability plot,
click on it.
Try it: Computer Printout Example.xlsx
What you get!
SUMMARY OUTPUT
Regression Statistics
Multiple R
0.906552235 = r
R Square
0.821836955
Adjusted R
Square
Standard Error
Observations
0.80402065
0.470339361
12 = n
Ignore this part of the print
out for now…you’ll get it
later in the spring!
ANOVA
df
SS
MS
F
1
10.20448
10.20448
46.12836
Residual
10
2.212191
0.221219
Total
11
12.41667
Regression
Significance F
4.79E-05
The y –
intercept (a)
Standard
Error
t Stat
4.88030303
0.289474
0.267132867
0.039332
Coefficients
Intercept
Age (mths)
P-value
Lower
95%
Upper
95%
16.85922
1.13E-08
4.235315
5.525291
6.791786
4.79E-05
0.179496
0.354769
The
slope (b)
The x-variable
Scatter plot with regression
line: (for school computers)
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Highlight all of the data, including labels
Click on Insert
Click on Scatter
Click on top left graph
To get the regression line you right click on
one of the points and choose trendline and
click enter.
Scatter plot with regression
line: (for windows 97)
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Click on Chart wizard
Scatter(xy)
1st one click Next
Highlight Data Range (do not include labels)
& press next
Type in labels for x & y
Press Next & Finish
To get line – click on point & press add
trendline
Normal Probability Plots
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Used to determine if the data is approximately
normal
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If it appears to be a straight line – then it’s
approximately normal
Weight (kg)
Normal Probability Plot
10
5
0
0
20
40
60
80
Sample Percentile
100
120
Find equation for the data below comparing the
intensity of a baby’s cry & their IQ.
ANOVA
df
SS
MS
F
Regression
1
2895.524 2895.524 20.28253
Residual
8
1142.076 142.7595
Total
9
Coefficient
s
Intercept
74.26985
Crying
2.604357
Significance
F
0.001993
4037.6
Standard
Error
t Stat
10.0478 7.391653
P-value
Lower 95%
Upper 95%
7.68E-05
51.09958
97.44012
0.578282 4.503613 0.001993
1.270837
3.937877
Residual Plot
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Looking for no – pattern in order for it to be a
good linear model
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Click on residual plot when doing the
regression to see it.
Homework
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Worksheet