I record all the tricks here to determine a qualitative (categorical), quantitative, nominal, ordinal, discrete, and continuous variable. First, two main groups of variables are qualitative and quantitative. In order to distinguish them, the criterion is “Can the answers of a variable be added?” For instance, you are concerning what is in your shopping bag. The […]
Archive | STAT 200
Quantiles and five number summary
Posted on November 13, 2015
I want to discuss a question popped up from my student when I was teaching how to find five-number summary. The case is simple, if we have only five number, (say 1, 2, 3, 4, and 5), what is the reason that calculators and the algorithm did not provide the five number summary as Minimum=1, […]
Confidence Interval for mean
Posted on October 8, 2015
I always tell students that the interpretation of 95% confidence interval, (a, b), should be as follows, Base on the same sampling procedure. I repeat the procedure 100 times, For each sample, a related confidence interval is calculated. (The interval may be different each time.) I have confident that approximately 95 out of 100 confidence […]