I am trying to group a data set by Sales rep and summing profit column but for some reason im getting the same number for each salesrep. That number makes sense, its the sum of the entire profit colum, but why is it the same for each rep? It shouldnt be.

Looks like the mistake is in how you structured the elements within the summarize() function.

It should be summarise(sum_profit = sum(profit))

See my example:

library(tidyverse)
sample_data <- txhousing # sample data set included in ggplot2
sample_data %>%
# in this case, total number sales for each city each year
group_by(city, year) %>%
# note the syntax for summarise using pipes %>%
summarise(sales_sum = sum(sales)) %>%
ungroup()
#> `summarise()` has grouped output by 'city'. You can override using the
#> `.groups` argument.
#> # A tibble: 736 × 3
#> city year sales_sum
#> <chr> <int> <dbl>
#> 1 Abilene 2000 1375
#> 2 Abilene 2001 1431
#> 3 Abilene 2002 1516
#> 4 Abilene 2003 1632
#> 5 Abilene 2004 1830
#> 6 Abilene 2005 1977
#> 7 Abilene 2006 1997
#> 8 Abilene 2007 2003
#> 9 Abilene 2008 1651
#> 10 Abilene 2009 1634
#> # ℹ 726 more rows