(Student's T-Test) | t value formula
TTest:Contents:WhatisaTtest?WatchthevideoforanoverviewoftheT-test:Thettesttellsyouhowsignificant[1]thedifferencesbetweengroupmeans[2]are.Itletsyouknowifthosedifferencesinmeanscouldhavehappenedbychance.Thettestisusuallyusedwhendatasetsfollowanormaldistribution[3]butyoudon’tknowthepopulationvariance[4].Forexample,youmightflipacoin1,000timesandfindthenumberofheadsfollowsanormaldistributionforalltrials.Soyoucancalculatethesamplevariance[5]fromthisdata,butthepopulationvarianceisunknown.Or,adrugco...
T Test: Contents:
What is a T test?Watch the video for an overview of the T-test:
The t test tells you how significant [1]the differences between group means [2]are. It lets you know if those differences in means could have happened by chance. The t test is usually used when data sets follow a normal distribution[3] but you don’t know the population variance[4].
For example, you might flip a coin 1,000 times and find the number of heads follows a normal distribution for all trials. So you can calculate the sample variance[5] from this data, but the population variance is unknown. Or, a drug company may want to test a new cancer drug to find out if it improves life expectancy. In an experiment, there’s always a control group[6] (a group who are given a placebo, or “sugar pill”). So while the control group may show an average life expectancy of +5 years, the group taking the new drug might have a life expectancy of +6 years. It would seem that the drug might w...