<h3>
Answer: Choice C</h3>
P = 11/40 + 1/4 - 1/20
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Explanation:
The formula we use is
P(A or B) = P(A) + P(B) - P(A and B)
In this case,
- P(A) = 22/80 = 11/40 = probability of picking someone from consumer education
- P(B) = 20/80 = 1/4 = probability of picking someone taking French
- P(A and B) = 4/80 = 1/20 = probability of picking someone taking both classes
So,
P(A or B) = P(A) + P(B) - P(A and B)
P(A or B) = 11/40 + 1/4 - 1/20
which is why choice C is the answer
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Note: P(A and B) = 1/20 which is nonzero, so events A and B are not mutually exclusive.
The parameter of the study's population is the 80% of all customers who shopped in the chain's stores that were interested in the home delivery service.
Population parameter is defined as any summary number that describes the entire population. It can be an average or a percentage/
The 1,000 customers that were surveyed are the sample of the population. They basically represent the population of the chain's customers.
Answer:
Let f_n be the number of rabbit pairs at the beginning of each month. We start with one pair, that is f_1 = 1. After one month the rabbits still do not produce a new pair, which means f_2 = 1. After two months a new born pair appears, that is f_3 = 2, and so on. Let now n 
3 be any natural number. We have that f_n is equal to the previous amount of pairs f_n-1 plus the amount of new born pairs. The last amount is f_n-2, since any two month younger pair produced its first baby pair. Finally we have
f_1 = f_2 = 1,f_n = f_n-1 + f_n-2 for any natural n 3.
