Compare the Z and t distributions

Lesson 14 covers Inferences on the Population Mean when the Population Standard Deviation is known.  The resulting hypothesis test and confidence interval are based on the Z-distribution, also called the Standard Normal Distribution. Lesson 15 covers Inference on the Population Mean when the Population Standard Deviation is unknown.   The sample standard deviation, S, will be used as an estimator for sigma, the population standard deviation, but when that occurs the test statistic is not Z, but t and the confidence interval form is also based on t, not Z.   Here are some details, Class Notes Z test and t test, with CI equations .

STAT 2023 Going Forward!

Greetings Students!  Our online adventure is starting with classes based on examples and videos.   SEE the TOP Right side link for a page labeled, “Classes.”   That page will identify what you need to be doing to learn the material.

SLIC Online:   SLIC is available through Canvas and you will receive email invitations to participate.  Each TA sends an invitation, so if the number of messages is too much then un-enroll and go directly to Conferences on the left side of Canvas to view the available options.

SI Sessions:  The SI Sessions are also online but you must enroll to view those options and get the invitation messages.  To enroll use this link,



Study for Exam Two

Exam Two is Thursday, March 5, 2020.  Begin to study by using this exam two review that represents all the types of distributions covered since exam one.   In the exam two review KEY the answers are provided, but additionally it indicates which past exam that the question came from.    Study Up!  Make an A!

STAT 2023 spring 2020 demographics

Course Roster 202020

A data graph to consider