Help I need 6 and 7 answered! 10 points!!

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

5. which description does not guarantee that a quadrilateral is a squar ajo is a parallelogram with perpendicular diagonals 0% has all sides congruent and all angles congruent o has all right angles and has all sides congruent 10% is both a rectangle and a rhombus 30%

Varies inversely with x. if y=8.5 when x=-1 find x when y=-1