Answer:
25
Step-by-step explanation:
use a Poisson process to model the arrival.
the mean rate of arrivals is λ=4.5
The standard deviation is calculated as:
σ==√λ =2.1213
The z-value for a 98% CI is z=2.3262.
If the 98% CI has to be within a error of 0.5 then:
Ul-Ll=2z*σ/√n=2*0.5=1
√n=z*σ=2.3262*2.1213=4.9346
√n=4.9346 and n = 4.9346^2=24.35 rounded to 25
The sample size needed is n=25.
