Answer: option d.
Step-by-step explanation:
You have the following formul given in the problem:
You know that:
The number of customers serviced in an hour by the technical support representative is 6 costumbers, therefore:
As the problem asked for the probability that a costumber will be on hold less than 30 minutes, we know that:
Substitute the values above into the formula.
Then, you obtain:
or 95%
Answer:
P(X≤5)=0.5357
Step-by-step explanation:
Using the binomial model, the probability that x adults from the sample, are pessimistic about the future is calculated as:
Where n is the size of the sample and p is the probability that an adult is pessimistic about the future of marriage and family. So, replacing n by 20 and p by 0.27, we get:
Now, 25% of 20 people is equal to 5 people, so the probability that, in a sample of 20 American adults, 25% or fewer of the people are pessimistic about the future of marriage and family is equal to calculated the probability that in the sample of 20 adults, 5 people of fewer are pessimistic about the future of marriage and family.
Then, that probability is calculated as:
P(X≤5)= P(1) + P(2) + P(3) + P(4) + P(5)
Where:
Finally, P(X≤5) is equal to:
P(X≤5) = 0.0018+0.0137 + 0.0480 + 0.1065 + 0.1675 + 0.1982
P(X≤5) = 0.5357