::: {.cell hash='03_Data_preprocessing_cache/revealjs/fraction_delayed2_deee2b3484b03a8edfc399cb390f2f83'}

```{.r .cell-code}
flights %>% 
  filter(!is.na(dep_delay)) %>%
  select(month,dep_delay) %>% 
  group_by(month) %>% 
  summarise(delayed = sum(dep_delay>0),all=n()) %>% 
  mutate(fraction_delayed=delayed/all) %>%
  select(month,fraction_delayed)
```
:::