Question

The probability that a corporation made profits in 2005 is 0.78 and the probability that a corporation made charitable contributions in 2005 is 0.23. assuming that these two events are independent, the probability (rounded to 4 decimal places) that a corporation made profits in 2005 or made charitable contributions in 2005, but not both is:

Answer 1

We know that these two events are independent, therefore:
P(profit and charity) = P(profit) * P(charity)
P(profit and charity) = 0.78 * 0.23 = 0.1794

Then,
P(profit or charity) = P(profit) + P(charity) - P(profit and charity)
P(profit or charity) = 0.78 + 0.23 - 0.1794
P(profit or charity) = 0.8306