Tutoring statistics, you might imagine everyday situations. The tutor brings up one. Let’s imagine we have two mile runners. Runner 1, called R1, has mean time 4:45, with standard deviation 10s; R2 has mean time 5:00 with standard deviation 12s. …

Statistics: how often can something “better” be expected to perform better? Read more »

Tagged with: ,

Tutoring statistics, distributions are of constant interest. The tutor brings up ten points about the chi-square distribution. The chi-square distribution may not be discussed much in a first-level stats course. It’s used to estimate or evaluate variance, rather than central …

Statistics: Ten facts about the chi-square distribution Read more »

Tagged with: ,

Tutoring statistics, linear regression is perennial. The tutor mentions an assumption it includes. When appropriate, linear regression models data by the equation y = a + bx + e, e being an error term due to variability. An inherent assumption …

Statistics: an assumption of the linear regression model Read more »

Tagged with:

Tutoring statistics, mean is used more than median. The tutor points out a reason why. In my post from November 30, 2014, I write about why the median might be preferred to the mean in some cases. For instance, the …

Estimation of expected value: why sample mean is usually preferred over median Read more »

Tagged with: , ,

Tutoring statistics, rules of usage are key. The tutor shares one about when the normal approximation to the binomial distribution can be used. The binomial distribution imagines a series of n trials, each with probability p of success and q=(1-p) …

Statistics: When can you use the normal approximation to the binomial distribution? Read more »

Tagged with: