By "no results" do you mean that the code doesn't run, or you get an empty table?
If it's the former, does reformating so that the line breaks in the code are removed help (this shouldn't matter, but the interpreter may be getting stuck with the empty lines between function calls)? E.g.:
sleep_cleaned <- brfss2013 %>%
filter(sleptim1 < 24) %>%
median_sleep = median(sleptim1),
avg_sleep = mean(sleptim1),
sleep_sd = sd(sleptim1),
n = n()
If it's the latter, are you sure that the criteria in
filter() will return results, i.e. are there any records in
sleptim1 is (strictly) less than 24? If not then you'll be summarising an empty
tibble and will get an empty one back.