A survey is taken of U.S. companies that do business with firms in India. One of the questions in the survey was: â€œApproximately how many years has your company been trading with firms in India?â€ A random sample of 44 responses to this question yields the following results.
Sample Size = 44
Sample Mean = 10.46 years
Sample Standard Deviation = 7.7 years
a. Compute the 95% confidence interval for the population mean number of years of trading with firms in India.
b. Interpret this interval.
c. How many firms should be sampled if we wish to generate a 95% confidence interval for the mean number of years of trading with firms in India that is accurate to within 1 year?