by Dawn Wright | Apr 16, 2018

by Dawn Wright | Apr 7, 2017

When we do not know the population standard deviation sigma, σ, and the sample size, n, is less than 30, we use the t-test to evaluate a claim. Consider the following problem: A scientist thinks the mean waste recycled by adults in the US is now more than one pound...
by Dawn Wright | Jan 30, 2017

Read the problem looking for keywords and values: What type of variable is the focus of the problem? Is it quantitative, e.g. a mean, or categorical, e.g. a proportion or percent? How many variables are of concern? Is(are) the population(s) standard deviation, sigma,...
by Dawn Wright | Feb 13, 2016

The Null and Alternative The most common problem I noticed on this assignment was caused by failing to properly identify the appropriate null and alternative hypotheses. In part, this is due to the Evans text’s somewhat confusing explanation of how to do this – the...