The number of traffic accidents per day on a certain section of highway is thought to be a Poisson distribution with a mean of 2.19 accidents.What is the standard deviation of the number of accidents?
A) 2.19
B) 4.80
C) 1.48
D) 3.14

Question

Quizplus · Accepted Answer

For a Poisson distribution, the standard deviation is the square root of the mean. Therefore, the standard deviation in this case is sqrt(2.19) = 1.48. Therefore, choice C is correct. Choice A (2.19) is incorrect because this is the mean, not the standard deviation. Choice B (4.80) and Choice D (3.14) are incorrect values and do not correspond to the Poisson distribution.

The Number of Traffic Accidents Per Day on a Certain