Remember that, for independent events, the probability that both occurr is the product of the individual probabilities.
a) Probability of being contacted: 78% = 0.78
Probaility of refusing: 1 - 22% = 1 -0.22 = 0.78
Combined probability: 0.78*0.78 = 0.6084
b) The probability of failing to contact or making contact and not geeting them to agree 1 - the probability of contacting and getting them to agree.
The probabilityof contacting and getting them to agree is 0.78*0.22 = 0.1716
The the answer to this question is 1 - 0.1716 = 0.8284
I already answered that question, here's the link:
brainly.com/question/10534199.
But if you still want the explanation, here it is:
"So if we want to measure probability, you have to add, then divide, like this:
First

, which gives us 18.
Then we see, that 6 is 1/3 of 18, so we conclude.
The answer is 33.33%.
Hope this helped!"
Is it not zero ???? ? ? ?