The probability of someone getting COVID-19 in Thailand when they have been given the COVID-19 vaccine is 0.1. Without the vaccine, the probability of getting COVID-19 is 0.4. If 30% of the population has been given the vaccine, what is the probability that a person chosen at random from the population will get COVID-19 in Thailand? (Round to nearest hundredth.)
My attempt:
(0.3)(0.1) + (0.7)(0.4) = 31 percent...
I think I'm doing this wrongly here. If I am wrong, what changes should I make?