::: {.cell hash='03_Data_preprocessing_cache/revealjs/unnamed-chunk-28_56e48896f52c3757c6e95637dc9328b2'}

```{.r .cell-code}
summarise(flights, avg_delay = mean(dep_delay, na.rm = TRUE))
```

::: {.cell-output .cell-output-stdout}
```
# A tibble: 1 × 1
  avg_delay
      <dbl>
1      12.6
```
:::
:::