A one-sample
t test
compares the mean of the sample to the null hypothesis mean.
To compare an individual
mean with a sample size of
n to a value
m,
use
![t equals . fraction x with macron above , negative m , over fraction s , over square root of n end fraction end fraction](images/t_test_one_sample.png)
where
![x with macron above](images/xbar.png)
is the sample mean of the observations and
s2 is
the sample variance of the observations.
For example, you want
to perform a one-sample
t test on the horsepower
values in the Sashelp.Cars data set. The null hypothesis is 300.