A medical test will be positive for 0.05% of people and negative for everyone else. Suppose a hospital will test 4000 patients each day. Use an appropriate approximation to find the probability that 5 people test positive tomorrow. (5SF)

Note that we have a constant probability, fixed number of tests, independent patients and only two outcomes, so we can write a binomial distribution X~Bin(4000,0.0005) where X is the random variable representing the number of patients who test positive.Use a Poisson approximation with L=np=2, so P(X=5) = ~(e^(-2)2^5)/5! = 0.036089

JM
Answered by John M. Maths tutor

2694 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

What is the integral of sin^2(x)?


Edexcel January 2007 - Question 4 (Rates and Differential Equations)


The equation of a circle is x^2-6x+y^2+4y=12. Complete the square to find the centre and radius of the circle.


integrate( x^3+4x^2+3)dx


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences