Layman’s Random Forests

I’m not a fan of the Top 40 style content on Quora, but a student in Dr. Leek’s Coursera class shared this absolute gem from Edwin Chen. I have not seen a better explanation: How do random forests work in layman’s terms? Suppose you’re very indecisive, so whenever you want to watch a movie, you ask […]

Unknown Variance Two-Tailed Test of Population Mean

Question The mean safety audit score of ACME Co. stores in New York (n=200) was 74.3pts February last year.  Suppose we decided to sample 22 out of the 200 stores one year later. We find that the sample mean is 78.6pts and the sample standard deviation is 3.2pts.  Can we reject the null hypothesis that […]

Correlation: Easy as 1-2-3?

I recently had a task to take a look at some assessment (audit) data. I was assuming, rather hoping for data with a normal distribution and thought it would be a quick case of Pearson correlation between two columns: “Duration” and “Score”. Just conjecture at this point as I did not understand what the assessment process […]