40 received a college degree. What’s the 99% confidence interval for the proportion of college graduates out of all the persons who attended college?

Q1. A random sample of 144 with a mean of 100 and a standard deviation of 60 is known from a population of 1,000. What is the 95% confidence interval for the unknown population ?Q2. A random sample of n = 10 flash light batteries with a mean operating life X=5 hr. And a sample standard deviation S = 1 hr. is picked from a production line known to produce batteries with normally distributed operating lives. What’s the 95% confidence interval for the unknown mean of the working life of the entire population of batteries?Q3. The NJ state education department finds that in a random sample of 100 persons who attended college, 40 received a college degree. What’s the 99% confidence interval for the proportion of college graduates out of all the persons who attended college?

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