2. 10,175 rounded to the nearest thousand 0 is the target, aka the number place I’m rounding to

Pls! does anybody know a shortcut for answering these types of questions in the future?

Weekly wages at a certain factory are normally distributed with a mean of $400 and a standard deviation of $50. find the probability that a worker selected at random makes between $450 and $500

To decrease an amount by 16% what single multiplier would you use