The number of absences per week by workers at a factory has the distribution $$$\operatorname{Po}(2.1)$$$. Find the probability that the number of absences in a 2-week period is at least 2. ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................ ........................................................................................................................................................

Mathematics

IGCSE&ALevel

CAIE

Exam No：9709_w20_qp_63 Year：2020 Question No：5(b)

Answer:

$\lambda=4.2$
$1-\mathrm{e}^{-4.2}(1+4.2)$
$=0.922(3 \mathrm{sf})$

6.1.1 use formulae to calculate probabilities for the distribution $\text { Po }(\lambda)$