I hope this isn't too long winded, I have most the answers, just need a check and some help on the last part.
Laser surgery to fix short-sightedness is becoming more popular. However, for some people, a second procedure is necessary. The following table lists the joint probability of needing a second procedure and whether the patient has a corrective lens with a factor (dioptre) of minus 8 or less.
This is supposed to be a table!
__________________ Vision corrective factor > -8, Vision corrective factor <= -8
1st procedure successful ___________0.66 ___________________0.15
2nd procedure required ____________0.05 ___________________0.14
a) Find the probability that a second procedure is required.
This is simply
b) Determine the probability that someone whose corrective lens factor is minus 8 or less does not require a second procedure.
This is
c) Are the events independent? Explain your answer.
I think the answer is yes, but I don't know how to explain