Hi everyone,

I found a similar threat which didn’t answer my question. I am working with temperature data from London and need to calculate the average temperature and the variance.

I am able to calculate and print the average/mean, but the variance function is not working. I checked my spelling 3 times and cannot find the error. It seems to me, the variance function is not properly loaded or something like that. Someone has an idea?

- See slide 25 and 26 on the screenshot, and the error message in the notebook ```

Error in variance(temp): could not find function “variance”

```
![Schermafbeelding 2020-05-25 om 14.43.24|690x326](upload://5oYTsYGdg8uDue9hunscJ5RzbQM.png)
```