A customer service desk with 1 worker is able to process an average of 9 customer inquiries per hour. An average of 6 customers arrive for help at the desk each hour. a) What is the probability that 3 customers will arrive in the next hour? b) What is the probability it will take longer than 7 minutes to serve a customer?
Contingency Table
A contingency table can be defined as the visual representation of the relationship between two or more categorical variables that can be evaluated and registered. It is a categorical version of the scatterplot, which is used to investigate the linear relationship between two variables. A contingency table is indeed a type of frequency distribution table that displays two variables at the same time.
Binomial Distribution
Binomial is an algebraic expression of the sum or the difference of two terms. Before knowing about binomial distribution, we must know about the binomial theorem.
Question 2) Waiting Line Analysis
A customer service desk with 1 worker is able to process an average of 9 customer inquiries per hour. An average of 6 customers arrive for help at the desk each hour.
- a) What is the
probability that 3 customers will arrive in the next hour? - b) What is the probability it will take longer than 7 minutes to serve a customer?
![**Understanding Probability**
In probability theory, the equation shown gives a hint on calculating the probability that a random variable \( X \) is greater than 2.
### Hint:
\[ P(X > 2) = P(X = 3) + P(X = 4) + \cdots + P(X = \infty) \]
This equation means that the probability of \( X \) being greater than 2 is the sum of the probabilities of \( X \) being equal to 3, 4, and so on, up to infinity.
### Key Concept:
**Recall that**
\[ \sum_{k=0}^{\infty} P(X = k) = 1.0 \]
This indicates that the sum of the probabilities of all possible values \( X \) can take on (from 0 to infinity) is equal to 1, representing the certainty that \( X \) will take on some value.
### Therefore:
\[ P(X > 2) = 1.0 - \sum_{k=0}^{2} P(X = k) \]
By this step, we understand that the probability of \( X \) being greater than 2 is equal to 1 minus the sum of the probabilities of \( X \) being 0, 1, or 2. This relation helps in simplifying the calculation of probabilities for values greater than a certain threshold by subtracting the sum of probabilities of other known values from 1.
By understanding these steps, students can effectively compute and analyze probabilities for ranges and intervals of random variables.](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2Ff64361a9-da35-4b1b-9c2d-68f8fe4a07c2%2F8d8436df-e755-4eb3-8ed4-0666b058f61f%2Fh60kep_processed.png&w=3840&q=75)
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