In: Statistics and Probability
Thirty percent of the engines manufactured on an assembly line are defective. Suppose engines are randomly selected one at a time and tested. (Round your answers to three decimal places.)
(a) What is the probability that the fourth nondefective engine will be found on the sixth trial?
(b) What is the probability that the fourth nondefective engine will be found on or before the sixth trial?
a)
P(4 non defective on 6th trial = 5C3*0.3^3*0.7^2 * 0.3
= 10 * 0.3^3 * 0.7^2 * 0.3
= 0.040
b)
P(4th non defective on or before the 6th trial) = 6C4 * 0.3^4 *
0.7^2
= 0.060