In 2003 the American Psychological Association conducted a survey (at research.apa.org) of a random sample of psychologists to estimate the mean incomes of psychologists with various academic degrees and levels of experience. Of the 16 psychologists who received a master's degree in 2003, the mean income was $43,834. It is known that the population of all psychologists who have a Masters' degree has a standard deviation of $16,870.
a. Construct a 90% confidence interval for the population mean.
b. Construct a 95% confidence interval for the population mean.