In: Economics
1. Profits of an industry consisting of 100 firms are normally distributed with a mean
of $1.5 million and a standard deviation of $120,000. Calculate:
(a) (5 points) P (X < $1 million)
Now suppose a random sample of 10 firms gave a mean profit of $900,000 and a sample standard deviation of of $100,000.
(b) Establish a 95% confidence interval for the true mean profit for the industry.
(c) Using the test of significance approach, will you reject or fail to reject the hypothesis that the true mean is $1.5 million? Please show your work.