Data quiz | Group by and summarize

❗️ INTRODUCTION TO DATA QUIZZES ❗️

• On each quiz attempt, the data is reshuffled. So you need to reimport the data each time you attempt a data quiz! This is to prevent you from using the answer corrections from one quiz attempt in the next quiz attempt.

🟠 IMPORTANT NOTE ABOUT THIS QUIZ 🟠

• In the final question, please use the signif() function in R for rounding to two significant figures. It uses the round half-to-even method (also known as Gaussian rounding or Bankers’ rounding) that, unlike traditional rounding methods, rounds .5 to the nearest even number. This prevents any bias in the sum of repeated roundings. You can use this function like this: signif(3.65, digits = 2). In that example, R will output 3.6, rounding to two significant figures.