Answer:
$3.25
Step-by-step explanation:
Given that:
Mean, λ = 1.4
Strike within next minute = $3 won
Strike between one and 2 minutes = $5
Strike more than 2 minutes = $1
Probability that next strike occurs within the next minute :
Using poisson :
P(x < 1) = 1 - e^-(λx) ;
P(x < 1) = 1 - e^-(1.4*1) = 1 - e^-1.4
P(x < 1) = 1 - 0.2465969
P(x < 1) = 0.7534030
Next strike occurs between 1 and 2 minutes :
(1 < x < 2) :
P(x < 2) - P(x < 1)
P(x < 2) = 1 - e^-(λx) ;
P(x < 2) = 1 - e^-(1.4*2) = 1 - e^-2.8
P(x < 2) = 1 - 0.0608100
P(x < 2) = 0.9391899
P(x < 2) - P(x < 1)
0.9391899 - 0.7534030 = 0.1857869
P(striking after 2 minutes)
P(x > 2) = e^-(λx) ;
P(x > 2) = e^-(1.4*2) = e^-2.8
P(x > 2) = 0.0608100
Amount charged :
(0.7534030 * 3) + (0.1857869 * 5) + (0.06081 * 1)
= 3.2499
= $3.25