Answer:
0.3233
0.09
Step-by-step explanation:
Given that :
Mean, λ = 0.25 for a 100,000 per week
For a population of 800,000 :
λ = 800,000 / 100,000 * 0.25 = 8 * 0.25 = 2 orders per week
Probability that technician is required after one week ;
After one week, order is beyond 2 ; hence, order, x ≥ 3
P(x ≥ 3) = 1 - [p(x=0) + p(x= 1) + p(x =2)]
P(x ≥ 3) = 1 - e^-λ(1 + 2¹/1! + 2²/2!)
P(x ≥ 3) = 1 - e^-2(1+2+2) = 1 - e^-2*5 = 1 - e^-10
P(x ≥ 3) = 1 - e^-2 * 10
P(x ≥ 3) = 1 - 0.6766764
P(x ≥ 3) = 0.3233
B.)
Mean, λ for more than 2 weeks = 2 * 2 = 4
P(x < 2) = p(x = 0) + p(x = 1)
P(x < 2) = e^-4(0 + 4^1/1!)
P(x < 2) = e^-4(0 + 4) = e^-4(5)
P(x < 2) = e^-4(5) = 0.0183156 * 5 = 0.0915
P(x < 2) = 0.09
