Paper 3 · June 2023 · Statistics: measurement scales, Poisson, chi-square, spatial autocorrelation
At a private clinic patients arrive at an average rate of 5 per hour, and arrivals follow a Poisson distribution. Calculate the probability that exactly 2 patients arrive in a given hour, correct to 4 decimal places.
Model answer
0.0842
Also accepted: 0.084, 0.0842 (4 d.p.)
Explanation
Poisson with mean m = 5: P(X = 2) = e^(-5) x 5^2 / 2! = 0.006738 x 25 / 2 = 0.0842.
Derived from ZIMSEC Advanced Level Geography 6037/3 Paper 3 Practical Test, June 2023 session, Q1