R code - How can I manipulate the df below to look like this this:

Question

Currently I wrote this code:

lc <- round(tabyl(x$Likelihood.to.Click,  show_na = FALSE),2)
lc$percent <- lc$percent * 100

and produced this chart:

But In need help manipulating it to create the below df (basically its summing the percentages of row 1 and 2, leaving 3 as is, and then summing 4 and 5:

Answer 1

First make your example reproducible using dput(lc) to pass the data:

lc <- structure(list(L2E = 1:5, n = c(7, 23, 84, 73, 33), pct = c(3, 
10, 38, 33, 15)), class = "data.frame", row.names = c(NA, -5L))

Now define the groups

groups <- list(1:2, 3, 4:5)
sumpct <- sapply(groups, function(x) sum(lc[x, 3]))
lc2 <- data.frame(group=seq(length(groups)), sumpct)
lc2
#   group sumpct
# 1     1     13
# 2     2     38
# 3     3     48

Note that row 3 is 38, not 32 and in rows 4 and 5, 33 + 15 = 48, not 54.