Question

Flaws in a carpet tend to occur randomly and independently at a rate of one every 200 square feet. What is the probability that a carpet that is 8 feet by 10 feet contains no flaws?

Answer 1

area = 80
1/200 = 0.2/80
so mean is 0.2 flaws per 80 sq. ft
\[P(k=0) = \frac{(0.2)^{0}e^{-.2}}{0!} = e^{-.2} = 0.8187\]

Answer 2

the answer is 0.6703

Answer 3

haha oops...are we using poisson distribution here?

Answer 4

yep

Answer 5

oh i had a stupid moment...can you spot my mistake?
hint: 80 goes into 200 how many times

Answer 6

2.5?

Answer 7

yeah...1/2.5 = 0.4
plug in 0.4 for mean instead, then it will work out :)

Answer 8

Thank you.