## Hypothesis Tests Simplified: The Big Picture of Statistics

The Big Picture of Statistics¹ The process of statistics starts when we identify what group we want to study or learn something about. We call this group the population. Note that the word “population” here (and in the entire course) is not just used to refer to people; it is used in the broader statistical […]

## Pick-a-Problem: Not given values for µ in 8.1.11

Question: I have hit the wall on a simple problem. I seem to be hitting these more often now. At any rate. 8.1.11, the difference between two means hypothesis test standardized test statistic requires µ1 – µ2. So, how does one calculate this when we are never given a value for μ? I used 0 for […]

## Finding Critical Values and Degrees of Freedom

Many students struggle to find critical values of z, t, and Chi-square for hypothesis tests. No matter how often I show them how to use the StatCrunch calculators to do this, they gravitate back to the tables. And make a lot of mistakes. To help a bit, I have created some Excel calculators that should […]

## Single-sample Hypothesis Test for a Proportion

Consider the following problem statement: An article in an online magazine states that 40% of home buyers found their real estate agent through referrals by a friend. However, a professor in a local college sampled 1000 home buyers and found that 426 chose an agent recommended by a friend. Does the data refute the claim […]

## How to determine the tail of a hypothesis test

[embedyt] http://www.youtube.com/watch?v=fgbChDkU4sQ[/embedyt] A quick and easy way to know whether you have a right-tailed, left-tailed, or two-tailed hypothesis test.