We have the fundamentals of factors – now it's time to work with bigger data!
Let's say we are now working for an online shop for astronomy enthusiasts. Recently, we conducted a survey of 1,000 customers who bought a new telescope from us. In addition to finding out whether these customers were satisfied with their purchases, we also had customers supply their age, marital status, employment status, and primary language. The survey results are now in memory, saved in the
Previously, we learned how to count the number of observations in groups using
count(). Let's count how many people are in each age group. To do this, we will write: