Announcements for 84 upcoming engineering conferences were randomly picked from a stack of IEEE Spectrum

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