An Economist Is Interested in Studying the Incomes of Consumers

Multiple Choice

An economist is interested in studying the incomes of consumers in a particular region.The population standard deviation is known to be $1,000.A random sample of 50 individuals resulted in an average income of $30,000.What sample size would the economist need to use for a 95% confidence interval if the width of the interval should not be more than $100?

A) n = 1537
B) n = 385
C) n = 20
D) n = 40