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st: Confidence intervals for predicted means versus predicted individual values
From
Adam Guerrero <[email protected]>
To
[email protected]
Subject
st: Confidence intervals for predicted means versus predicted individual values
Date
Mon, 24 Feb 2014 18:05:25 -0600
Dear Statalist,
I have a combination Stata/stats question. I am trying to reproduce an example
in Bowerman et al.'s "Forecasting, Time Series, and Regression." My
ultimate goal is to locate a command in Stata that gives confidence
intervals for conditional mean and individual dependent variable
predictions.
I have inputted the following data into Stata
. input temp fuelcons
. 28 12.4
. 28 11.7
. 32.5 12.4
. 39 10.8
. 45.9 9.4
. 57.8 9.5
. 58.1 8
. 62.5 7.5
. end
After regressing fuelcons on temp, I can obtain predicted values of
fuelcons using
. regress fuelcons temp
. predict pfuelcons
I can also get the standard errors of the predicted mean using
. predict pmfuelcons, stdp
Finally, I can get the standard errors of the predicted individuals
fuelcons values using
. predict pyfuelcons, stdf
I know that I can use this information to obtain a confidence interval
for the conditional mean and a confidence interval for a particular
value of fuelcons given a value for temp in the data.
My question is whether there is a command that will allow me to
estimate a 95% confidence interval for the mean value of fuelcons
given a particular value of temp that is not included in the data, but
is in the range of temp (e.g., given a temp of 40).
I would also like to get a 95% confidence interval for an individual
value of fuelcons given a particular value of temp that is not
included in the original data, but is in the range of temp (e.g.,
given a temp of 40).
The confidence interval for the mean value of fuelcons when temp
equals 40, and the prediction interval for an individual value of
fuelcons when temp equals 40 are computed automatically in MINITAB as
Fit SE Fit 95% CI 95% PI
10.721 .241 (10.130, 11.312) (9.015, 12.427)
Is it possible to do this in Stata with a single command?
I am a bit worried that I am overlooking something simple in, so I
apologize in advance if that's the case, and thank you for assisting
with my question.
Regards,
Adam Guerrero
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