Answer:
95% confidence interval: (0.325 ,0.383)
Step-by-step explanation:
We are given the following in the question:
Sample size, n = 231
Sample mean = 0.354 ppm
Sample standard deviation = 0.231 ppm
95% confidence interval:
Putting the values, we get,
Answer:
a) The probability that at least 5 ties are too tight is P=0.0432.
b) The probability that at most 12 ties are too tight is P=1.
Step-by-step explanation:
In this problem, we could represent the proabilities of this events with the Binomial distirbution, with parameter p=0.1 and sample size n=20.
a) We can express the probability that at least 5 ties are too tight as:
The probability that at least 5 ties are too tight is P=0.0432.
a) We can express the probability that at most 12 ties are too tight as:
The probability that at most 12 ties are too tight is P=1.