Atennis club charges a monthly membership fee of $150 and charges it members $10 per hour to use a court. there's also $500 fee to become a member. stella joined the tennis club last spring, and she has been a member for 5 months. she has been playing 10 hours of tennis each month. stella values an hour of her time at $20. during a boring afternoon meeting, stella thinks about reserving a court to work on her serve for an hour tonight. what's stella's opportunity cost of working on her serve for an hour?

Portia grant is an employee who is paid monthly. for the month of january of the current year, she earned a total of $8,388. the fica tax for social security is 6.2% of the first $118,500 earned each calendar year and the fica tax rate for medicare is 1.45% of all earnings. the futa tax rate of 0.6% and the suta tax rate of 5.4% are applied to the first $7,000 of an employee's pay. the amount of federal income tax withheld from her earnings was $1,391.77. what is the total amount of taxes withheld from the portia's earnings?