## Exam 1 Available Saturday thru Monday

Exam 1 on Canvas is available Saturday, Sept 12 through Monday, Sept 14.  There is an exam review ViDEO posted in the top module in the Canvas site.  Lesson 5 material is prevalent in the exam.  Watch the video lecture and video example in the Lesson 5 module.

## Quiz 3 Reopened, Quiz 4 Available

Quiz 3 that covers Lesson 5 is reopened since that material will be prominent on the exam.    Three additional attempts can be made on Quiz 3.   Quiz 4 that covers Lesson 6  is now currently available.   You have until Monday night, September 14 to complete these quizzes.

Let’s have a great week!

## Welcome to STAT 2023 Fall 2020!

Greetings Students!

Welcome to STAT 2023, Elementary Statistics for Business and Economics.  The syllabus for STAT 2023 for fall 2020 is now posted.  Also see Lessons for Exam One for hyperlinked course materials.  Let’s have a great semester!   Your stat teacher, Dr. Masters

## Lesson 17 The Differences between Two Population Means

Lesson 17 covers inferences on the difference between two means.   On the Classes page there are summary notes, three examples, and some videos to watch.

## 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 .