The number of accidents per week at a hazardous intersection varies with mean 2.2 and standard deviation of 1.4. The distribution takes only integers and most definitely not normal. Let x-bar be the mean of accidents per week at the intersection during one year (52 weeks). What is the approximate probability that x-bar is less than 2

Approximate probability that is less than 2 = 0.1515

Step-by-step explanation:

Given -

Mean = 2.2

Standard deviation = 1.4

Sample size ( n ) = 52

Let   be the mean of accidents per week at the intersection during one year (52 weeks) .

probability that is less than 2 =

 =   Putting

                 =    ( Using Z table )

                 = 0.1515

the answer   is 200

step-by-step explanation:

this is a problem about poisson probabilities.   i don't know if you've

already studied poisson distributions, or if you have a place to look

to read more about the subject.  

here's how you can see a poisson distribution coming.   when there are

a lot of events that may happen at any time (or any place), and when

you're counting how many of them happen at a particular time (or a

particular place), and each event is independent of the others, then

the result is a poisson distribution.   this is roughly true for the

chocolate chips; one chip being in a cookie has only a small effect on

the probability that another chip will be in the cookie.

once you know you have a poisson distribution, you know a lot.   there

is only one parameter to a poisson distribution, so if you know the

mean, you know everything.   the form of the distribution is

  probability of n chips = {[e^(-x)]*(x^n)} / (n! )

answer: i'm not going to give you the answer, but some hints to work it out.

step-by-step explanation: so, if there is a straight line that means that the line angle is 180°. so we subtract the 2 angle measures provided, (15 and 38) from 180. so the answer is 180 - (38 + 15). (you have to solve the equation)