How do I identify the standard deviation and variance from a frequency table given only the percentage of each x value?

Lin is shopping for a couch with her dad and heard him ask the salesperson “how much is your commission? ” the salesperson says that her commission is 5 1/2% of the selling price. a. how much commission will the salesperson earn by selling a couch for $495? b. how much money will the store get from the sale of the couch?

Robin spent 25% more time on his research project than he had planned he’s been an extra h ours on the project which of the following expressions could represent the number of hours rob actually spent on the project

Andy has $310 in his account. each week, w, he withdraws $30 for his expenses. which expression could be used if he wanted to find out how much money he had left after 8 weeks?