Table of contents
- 1. Intro to Stats and Collecting Data55m
- 2. Describing Data with Tables and Graphs1h 55m
- 3. Describing Data Numerically1h 45m
- 4. Probability2h 16m
- 5. Binomial Distribution & Discrete Random Variables2h 33m
- 6. Normal Distribution and Continuous Random Variables1h 38m
- 7. Sampling Distributions & Confidence Intervals: Mean1h 3m
- 8. Sampling Distributions & Confidence Intervals: Proportion1h 12m
- 9. Hypothesis Testing for One Sample1h 1m
- 10. Hypothesis Testing for Two Samples2h 8m
- 11. Correlation48m
- 12. Regression1h 4m
- 13. Chi-Square Tests & Goodness of Fit1h 20m
- 14. ANOVA1h 0m
5. Binomial Distribution & Discrete Random Variables
Poisson Distribution
Struggling with Statistics?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
A baker wants to predict how many customers will enter their bakery. On average, 2 customers come into the bakery every 15 minutes. Find the probability that exactly 5 customers will enter the bakery
(B) 4 or fewer customers enter the bakery in a random 15 min period.
A
B
C
D

1
Step 1: Recognize that this is a Poisson distribution problem. The Poisson distribution is used to model the number of events (e.g., customers entering a bakery) occurring in a fixed interval of time or space, given a known average rate (λ). Here, the average rate (λ) is 2 customers per 15 minutes.
Step 2: Recall the Poisson probability formula: P(X = k) = (λ^k * e^(-λ)) / k!, where k is the number of events (e.g., customers), λ is the average rate, and e is the mathematical constant approximately equal to 2.718.
Step 3: For part (A), calculate the probability of exactly 5 customers entering the bakery in 15 minutes. Substitute λ = 2 and k = 5 into the formula: P(X = 5) = (2^5 * e^(-2)) / 5!. Simplify the expression step by step to find the probability.
Step 4: For part (B), calculate the probability of 4 or fewer customers entering the bakery. This is the cumulative probability P(X ≤ 4), which is the sum of probabilities for X = 0, 1, 2, 3, and 4. Use the Poisson formula for each value of k (0 through 4) and sum the results: P(X ≤ 4) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4).
Step 5: After calculating the individual probabilities for part (B), add them together to find the cumulative probability. Compare the results to the provided answer choices to identify the correct one.
Watch next
Master Introduction to the Poisson Distribution with a bite sized video explanation from Patrick
Start learningRelated Videos
Related Practice