[DuskStar]

Just to point out:

1. Not a spurious correlation - Siemens sensors are in fact associated with increased failure rates in the dataset and if you continue to sample data with the same methodology this correlation will continue. You need to fix your data collection methodology, but it's not a spurious correlation.

2. See #1.

3. See #1.

4. The original problem statement said that a low percentage of unfailed turbines used Siemens sensors, and a high percentage of failed turbines used Siemens sensors. So 'you use mostly Siemens sensors' would imply that most of your turbines have failed, which seems a little unlikely to me.