Answer:
a) 0.02739
b) 0.00034
Step-by-step explanation:
If it is believed that at least 6 of the 10 pints are usable, then the 75% of “good” pints that can be used from this sample reduces to 60% of 75% = 0.6*0.75 = 0.45
Now for this sample we use a binomial distribution with probability of “success” (finding a “good” pint) of 0.45% and
the probability of getting exactly r good pints out of 10 is
where
are combinations of 10 taken r at a time.
a)
The probability that at least 8 of the pints are usable is P(r>7)
b)
Here we want P(r=10)