The Chartered Financial Analyst (CFA) designation is fast becoming a requirement for serious investment professionals. Although it requires a successful completion of three levels of grueling exams, it also entails promising careers with lucrative salaries. A student of finance is curious about the average salary of a CFA charterholder. He takes a random sample of 25 recent charterholders and computes a mean salary of $138,000 with a standard deviation of $45,000. Use this sample information to determine the 90% confidence interval for the average salary of a CFA charterholder.