SOLUTION: Only 4% of people have Type AB blood. A bloodmobile has 12 vials of blood on a rack. If the dis- tribution of blood types at this location is consistent with the general popu

Algebra ->  Probability-and-statistics -> SOLUTION: Only 4% of people have Type AB blood. A bloodmobile has 12 vials of blood on a rack. If the dis- tribution of blood types at this location is consistent with the general popu      Log On


   



Question 350181: Only 4% of people have Type AB
blood. A bloodmobile has 12 vials of blood on a rack. If the dis-
tribution of blood types at this location is consistent with the
general population, what’s the probability they find AB blood in:

a) None of the 12 samples?
b) At least 2 samples?
c) 3 or 4 samples?

Answer by edjones(8007) About Me  (Show Source):
You can put this solution on YOUR website!
Let x=.04 and y=.96
expand (x+y)^12
.
a) y^12=.6127
.
b) 12xy^11+y^12=.9191
1-.9191=.0809
.
c) 12C3=220, 12C4=495
220x^3y^9+495x^4y^8=.0106
.
Ed