Warning message being showing for the Statistical Inference exercises

[Pak Jiddat]

When completing the Statistical Inference exercise, the following warning message shows up:

warning messages from top-level task callback 'mini'
Warning messages:
1: Use of `dat$y` is discouraged. Use `y` instead. 
2: Use of `dat$y` is discouraged. Use `y` instead. 
3: Use of `dat$y` is discouraged. Use `y` instead.