Announcements for 84 upcoming engineering conferences were randomly picked from a stack of IEEE Spectrum magazines. The mean length of the conferences was 3.94 days, with a standard deviation of 1.28 days. Assume the underlying population is normal.
Define in words the random variable X.
Which distribution should you use for this problem? Why?
Construct a 95% confidence interval for the population mean length of engineering conferences.
-state the confidence interval
-sketch the graph
-calculate the error bound