Question

Use the Poisson Distribution Formula to find the indicated probability.

For a certain type of fabric, the average number of defects in each square foot of fabric is 1.8. Find the probability that a randomly selected square foot of the fabric will contain at least two defects. Round your answer to four decimal places.

Hint: The answer is the complement of the probability that there is at most 1 defect

Answer 1

The distribution is:

	1.8	mean rate of occurrence
		cumulative
X	P(X)	probability
0	0.1653	0.1653
1	0.2975	0.4628
2	0.2678	0.7306
3	0.1607	0.8913
4	0.0723	0.9636
5	0.0260	0.9896
6	0.0078	0.9974
7	0.0020	0.9994
8	0.0005	0.9999
9	0.0001	1.0000
10	0.0000	1.0000
11	0.0000	1.0000
12	0.0000	1.0000
13	0.0000	1.0000
	1.00000

Required probability = 0.5372