Based on this table, the probability that the physician is a man is 78% Now, if the physician is a man and 35-44 years old, he’s already included in that 78%, so we only need to now consider the possibility that they physician is female and 35-44 years old: 8%.
So the total probability is 78% (male) + 8% (female and 35-44) = 80%
This can also be found by adding up all the individual probabilities in your table:
Find a common denominator that both of the fractions can use. An easy way to do this is simply multiply the denominators together. So for 3/5 you would multiply by 3 to get the fraction 9/15 and then multiply 1/3 by 5 to get 5/15. Add both 9/15 and 5/15 to then get 14/15.