SOLUTION: Need some help with this question please! I know I have to know 0.9 is what isn't defective for (a) and 0.85 for (b), but from there I am lost. A stationary store has decided to

Question 1039790: Need some help with this question please! I know I have to know 0.9 is what isn't defective for (a) and 0.85 for (b), but from there I am lost.
A stationary store has decided to accept a large shipment of ball-point pens if an inspection of 17 randomly selected pens yields no more than two defective pens.
(a) Find the probability that this shipment is accepted if 10% of the total shipment is defective.
(b) Find the probability that this shipment is not accepted if 15% of the total shipment is defective.

Answer by Boreal(15235) (Show Source): You can put this solution on YOUR website!
Probability there are 0=0.9^17=0.1668
there is 1= 17*.9^16*.1, which is 17C1(0,9)^16*(0.1)^1=0.3150
there are 2=17C2(0.9)^15(0.1)^2=0.2800; 17C2= 17*16/2=136
The probability is their sum, or 0.7618.
-------------------------------
Analogous for 0.85
.85^17=0.0631
17(.85^16)(.15^1)=0.1893
136*(.85^15)(.15^2)=0.2673
This sum is 0.5197. It is less, as it should be because there is a higher probability of defective pens and 0,1,2 defects will have a lower probability.
it is nCk(p)^(n-k)*(1-p)^k
RELATED QUESTIONS
Hi, please help me out with this question. It is very confusing and I don't know how to... (answered by ikleyn,Theo)

Hello, I need help with my summer assignment. It's a two-part question. The first part... (answered by josgarithmetic,ikleyn)

I need to solve by factoring and using the principle of zero products. question:... (answered by ewatrrr)

Please Help. I have a textbook and it takes me through the steps on what I need to do,... (answered by Fombitz)

I am halfway through this problem and have been working on it/been stuck on it for quite... (answered by josgarithmetic,MathTherapy)

Hello. I was hoping you could please help me. I need some help with graphing f: x -->... (answered by Fombitz)

I need to write in standard form and determine the values of a, b, and c, for question #4 (answered by checkley75)

For each of the limits determine whether the limit exists as a number, as an infinite... (answered by Boreal)

Can somebody please help me! Find all real solutions to (a) x^2 + x + SQRT(x^2 +... (answered by funmath)