2 Sample T Interval & T Test to Compare Means, TI 84 Calc, Spreadsheet, Pooled & Unpooled Variances

What is the formula for a 100(1-α)% confidence interval to estimate the difference of two population means μ1 - μ2? How about to compute the t-statistic to test the null hypothesis that the population means are equal H0: μ1 = μ2? What are the degrees of freedom? It depends on whether the sample variances s1^2 and s2^2 are pooled or not to get the pooled variance. The degrees of freedom is either n1 + n2 - 2 (pooled) or obtained with technology (unpooled), such as in a spreadsheet like Excel. Links and resources =============================== 🔴 Subscribe to Bill Kinney Math: https://www.youtube.com/user/billkinn... 🔴 Subscribe to my Math Blog, Infinity is Really Big: https://infinityisreallybig.com/ 🔴 Follow me on Twitter:   / billkinneymath   🔴 Follow me on Instagram:   / billkinneymath   🔴 You can support me by buying "Infinite Powers, How Calculus Reveals the Secrets of the Universe", by Steven Strogatz, or anything else you want to buy, starting from this link: https://amzn.to/3eXEmuA. 🔴 Check out my artist son Tyler Kinney's website: https://www.tylertkinney.co/ AMAZON ASSOCIATE As an Amazon Associate I earn from qualifying purchases.