Hi there!

I have the following dataset that I am trying to reduce to a single row by taking the mean of all the depths. When I try to use `summarise()`

it gives me an error:

```
Error: Problem with `summarise()` input `..2`.
x Input `..2` must be a vector, not a function.
i Input `..2` is `mean`.
```

What I want it to look like is a dataframe with a single row and two columns: the SITE_ID and the MEAN_DEPTH_M.

Here's the dataset:

```
secchi <- structure(list(SITE_ID = c("GBA20-10501", "GBA20-10501", "GBA20-10501",
"GBA20-10501", "GBA20-10501", "GBA20-10501"), DEPTH_M = c("2.3",
"2.0", "2.2", "2.0", "2.2", "2.0")), row.names = 4:9, class = "data.frame")
```

I tried this:

`secchi %>% summarise(DEPTH_M, mean, na.rm=T)`

Can anyone help me figure this out?

Thanks so much!