Stat 411/511 Inclass Assignment
Regression October 12, 2015
Describe these relationships:
Men Rate Women
Women Rate Men
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mostAttractive
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selfAge
1. Big Bang: Nebula are receeding from Earth at some velocity, and each is a certain distance
away. (Data summary and plot)
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velocity
Min.
:-220
1st Qu.: 165
Median : 295
Mean
: 373
3rd Qu.: 538
Max.
:1090
distance
Min.
:0.030
1st Qu.:0.408
Median :0.900
Mean
:0.911
3rd Qu.:1.175
Max.
:2.000
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Recession Velocity vs. Distance
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distance
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−500
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1000
velocity
Model: µ{Y |X} = β0 + β1 X
Y is response, X is explanatory variable. This is simple linear regression (SLR).
Add a line to the plot which best fits these data.
If all matter started at one point, the line should go through the origin. How close is your
line to the point (0, 0)?
Compare lines with a neighbor. How do we determine the line of best fit?
µ{Distance} = β0 + β1 Velocity. Is β0 = 0?
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6.5
7.0
2. Meat Processing and pH.
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pH
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6.0
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5.5
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6
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time
Again draw your guess of the best line fitting these data. Guess pH when time = 3 hours
(interpolating doesn’t work with an ANOVA model).
Guess how long it takes to bring pH down to 6.
Sampling Distribution:
Consider repeating the study all over again. We would get new slope and intercept estimates.
How different might they be?
Might we get β0 = 0 for big bang?
Might we get 3 hours is long enough to bring pH down to 6?
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