link to mindfulness dataset: https://quantpsych.net/data/mindfulness.csv
# learning objectives
# tidyverse vs. R's way of doing things
# what filter, arrange, select, mutate, and summarize do
# selecting a range of columns (e.g., x1:x10)
# selecting "not" columns (e.g., -(x1:x10))
# understand auxiliary functions:
# starts_with, ends_with, contains, group_by, desc
# understand comparisons (&, |, ==, !=, %in%)
# Exercise
# filter to those over 18, create sum scores for mindfulness/stress/depression,
# select only age and the total score columns, then summarize by group