Geologists estimate the since the most cooling of a mineral by counting the number of uranium fission tracks on the surface of the mineral. A certain mineral specimen is of such an age that there should be an average of 6 tracks per cm2 of surface area. Assume the number of tracks in an area follows a Poisson distribution. Let X represent the number of tracks counted in 1 cm2 of surface area. Find

a. P (X = 7)

b. P (X ≥ 3)

c. P (2<X<7)

d. μX

e. σX

Solution

Step 1 of 6

Let X represents the no. of tracks

Here X follows poisson distribution with average of 6 tracks

The pmf of poisson distribution is P(X)=, X=0,1,2,..............

Here =6