Can you help answers these probability questions?

1. A certain disease has an incidence rate of 0.6%. If the false negative rate is 8% and the false positive rate is 2%, compute the probability that a person who tests positive actually has the disease.
2. A bag contains 2 gold marbles, 10 silver marbles, and 20 black marbles. The rules of the game are as follows: You randomly select one marble from the bag. If it is gold, you win $6, if it is silver, you win $4. If it costs $1 to play, what is your expected profit or loss if you play this game?
3. The PTO is selling raffle tickets to raise money for classroom supplies. A raffle ticket costs $3. There is 1 winning ticket out of the 230 tickets sold. The winner gets a prize worth $88.Round your answers to the nearest cent.

a. What is the expected value (to you) of one raffle ticket? $

b. Calculate the expected value (to you) if you purchase 10 raffle tickets. $

c. What is the expected value (to the PTO) of one raffle ticket? $

d. If the PTO sells all 230 raffle tickets, how much money can they expect to raise for the classroom supplies?

4.Last one: A company estimates that 0.5% of their products will fail after the original warranty period but within 2 years of the purchase, with a replacement cost of $350.

a. If they offer a 2 year extended warranty for $51, what is the company's expected value of each warranty sold?