Respuesta :
Answer:
Probability that fewer than 2 of these parts are defective is 0.604.
Step-by-step explanation:
We are given that at a certain auto parts manufacturer, the Quality Control division has determined that one of the machines produces defective parts 19% of the time.
A random sample of 7 parts produced by this machine is chosen.
The above situation can be represented through Binomial distribution;
[tex]P(X=r) = \binom{n}{r}p^{r} (1-p)^{n-r} ; x = 0,1,2,3,.....[/tex]
where, n = number of trials (samples) taken = 7 parts
r = number of success = fewer than 2
p = probability of success which in our question is % of defective
parts produced by one of the machine, i.e; 19%
LET X = Number of parts that are defective
So, it means X ~ Binom(n = 7, p = 0.19)
Now, probability that fewer than 2 of these parts are defective is given by = P(X < 2)
P(X < 2) = P(X = 0) + P(X = 1)
= [tex]\binom{7}{0}\times 0.19^{0} \times (1-0.19)^{7-0}+ \binom{7}{1}\times 0.19^{1} \times (1-0.19)^{7-1}[/tex]
= [tex]1 \times 1 \times 0.81^{7} +7 \times 01.9^{1} \times 0.81^{6}[/tex]
= 0.604
Therefore, the probability that fewer than 2 of these parts are defective is 0.604.
