That is, a left tail test should have a negative critical value, a right tail test should have a positive critical value, and a two tail test should have both a positive and negative critical value. There should always be as many critical values as tails and the signs should agree. Read your critical value(s) from the table.If you're using the normal distribution, go all the way to the bottom row. Use that column and go down until you find the proper degrees of freedom.Scan across that row and find your significance level α.Pick the appropriate row based on the type of test. At the top of the t-table, there is a row for one tail areas and a row for two tail areas.This comes from the alternative hypothesis, H 1. Whether it is a one tail (left tail or right tail) or a two tail test.The default value used if no other value is given is α = 0.05. If you use a t distribution, you will also need to know the degrees of freedom. This is the standard normal distribution (z) for proportions or the Student's t distribution (t) for means. To look up a critical value, you need to know three things.
You will need to put the dates on the assignment you turn in. Storing the sample in the picked columnĪlthough the actual dates aren't necessary for the analysis, you may want to leave them in the worksheet and then put the data value for that date in the column next to it, matching dates with values.You want to sample 16 rows (use the number of dates you need).Choose Calc / Random data / Sample from columns.You may want to use something more appropriate, especially if you have more than one sample you're going to be taken (as in the case of the temperature question). You want each value listed once and the entire sequence listed once.Choose Calc / Make Patterned Data / Simple Set of Date/Time Values.This example will assume you want to pick from dates from Januthrough December 31, 2005. There are a couple of problems that ask you to randomly select 16 dates for a certain time period.
#Minitab t test how to
There are common tasks needed for each of the questions, so I'm going to explain how to do each task in its own section rather than within the context of a particular problem. This document is set up a little bit differently than other set of instructions. Minitab Instructions for Hypothesis Testing Technology Exercises Minitab Instructions for Hypothesis Testing Technology Exercises