If you are going to an "x-bar" chart based on range statistics and you are using a sample size of 12 for your charting purpose, what is the A2 factor for the "X-bar" chart

Jackson earns $25 per hour as a tutor at the college library. he set a weekly spending budget of $130 each week and puts the remaining money in his savings account. how many hours must he work this week to have at least an extra $50 to put in his savings account