Editing Statistics and Statistical Programming (Fall 2020)/pset4 (section)

=== PC3. Confidence interval of a mean ===
Again, using the variable <code>x</code> from your Problem Set 2 data, compute the 95% confidence interval for the mean of this vector "by hand" (i.e., in R) using the normal formula for the [https://en.wikipedia.org/wiki/Standard_error#Standard_error_of_the_mean standard error of a mean]: <math>(\frac{\sigma}{\sqrt{n}})</math>, where <math>\sigma</math> is the standard deviation of the sample and <math>n</math> is the number of observations (''Bonus:'' Do this by writing a function.).

==== Compare and explain ==== 
Compare the mean of <code>x</code> from your Problem Set 2 data—and your confidence interval from PC3—to the mean of <code>x</code> in the dataset for the present Problem Set. Is the mean for the aggregate dataset (this week's data) within the confidence interval for your Problem Set 2 data? Do you find this surprising? Why or why not? Explain the conceptual relationship of these values to each other.