math
posted by Anonymous .
I was given a table that showed a simple random sample of adults' age and annual income living in suburb of a large city.
a) What is the probability that a person chosen at random from those in this sample will be the 3145 age category? The answer I got is .43 or 43%.
b) What is the probability that a person chosen at random from those in this sample whose incomes are over $50,000 will be in the 3145 age category? I found this to be .365, or 36.5%.
c) Bsed on your answers in parts a and b, is annual income independeent of age category for those in this sample? Explain. How do I prove this? I don't know what to do for this part.

It is not possible to critique answers a or b because the table is not here.
On c, again we need the table. 
Here is the table:
Annual income
Age 25K35K 35,00150K Over 50K
2130 8 15 27
3145 22 32 35
4660 12 14 27
Over 60 5 3 7