Answer:
Here, n = 51
Probability of success, p = 0.02
Probability of failure, q = 0.98 (= 1−0.2)
The entire shipment is accepted if at most 2 batteries do not meet specification. That is we have to find P(x ≤ 2).
probability = P(x=0)+p(x+1)+p(x=2)
=(0.02)^0(0.98)^51-0+(0.02)^1(0.98)^51-1+(0.02)^2(0.98)^51-2.
= 0.0071 +0.0073+0.00015
= 0.0145
= 1.45%