Yes, it is 450.
Now look that up in the z-table to get the percentage discarded.
The 68-95-99.7 Rule will get you close.
Say I have a bottle of beer that has mean weight of 500g with an SD of 25g. The QC decides to discard all the bottles that are more than 2SD lighter the mean weight, what percentage of the salt will be discarded, and what is the cut off value based on the empirical rule??
I know here that all bottles that are less than 450g will be discarded right, so that's the cut off value? Am I right?
How about finding the percentage?