A/B Testing for ShoeFly.com  Step 4
https://www.codecademy.com/courses/learnr/projects/raggregatesshoefly
I continue to get this error when I execute my code, any assistance would be greatly appreciated
# define clicks_by_utm here:
percentage_by_utm < clicks_by_utm %>%
group_by(utm_source) %>%
mutate(percentage = count/sum(count))
Error in sum(count): invalid 'type' (closure) of argument
Hide
percentage_by_utm
Error in eval(expr, envir, enclos): object 'percentage_by_utm' not found
I tried to solve for this by adding: summarize(count = n() ) %>%
above the mutate line
but that set each of the percentages to 25% rather than the % for click rate by UTM_Source
Here is the instructions for step 4
To find the percentage of people who clicked on ads from each utm_source
, we need to add a new column to ad_clicks
that stores the count
of clicks (or the count
of not clicking) divided by the total number of ad views.
Group clicks_by_utm
by utm_source
and pipe the result into mutate()
, creating a new column percentage
that is defined as count/sum(count)
.
Save your result to percentage_by_utm
and view it. Open the hint for a description of the percentage_by_utm
data frame.
Hint
To group together the rows of clicks_by_utm
with the same value for utm_source
with group_by()
:
percentage_by_utm < clicks_by_utm %>% group_by(utm_source) %>%
To add a column that stores the percentage of users who did or did not click on the ad, pipe the result from the grouping into mutate()
and create a new column percentage
defined as count/sum(count)
:
percentage_by_utm < clicks_by_utm %>% group_by(utm_source) %>% mutate(percentage = count/sum(count))

count
represents the number of users who did or did not click on an ad 
sum(count)
represents the total number of users who saw the ad
percentage_by_utm
will now contain the click and nonclick rates for each utm_source
/ ad_clicked
grouping.