Cyclistic Project - Difference between member/casual riders by percent

I'm pretty new to (r) and I'm going through the Google Data Analytics Capstone Project and have the following code chunk below. In looking at it, the difference between casual/members is pretty drastic. I'm trying to figure out how to calculate the percentage difference between casual/members by day of the week. I know I need to insert a column ride_length_diff but I'm unsure of the code.

aggregate(bike_rides_v3$ride_length ~ bike_rides_v3$member_casual + bike_rides_v3$day_of_week, FUN = mean)

dput(head(bike_rides_v3, 10)[c("day_of_week", "ride_length")])
structure(list(day_of_week = structure(c(7L, 4L, 5L, 5L, 7L,
7L, 2L, 5L, 7L, 1L), levels = c("Sunday", "Monday", "Tuesday",
"Wednesday", "Thursday", "Friday", "Saturday"), class = c("ordered",
"factor")), ride_length = c(625, 244, 80, 702, 43, 3227, 335,
400, 151, 433)), row.names = c(NA, 10L), class = "data.frame")

Please provide a reprex. See the FAQ. Most people won't try to gin up some day to illustrate the answer.