6. in 2003, a survey conducted by the american psychological association examined the incomes of those with various degrees. of the 31 re? pondents with masters degrees, the mean income was $43,834 and the standard deviation was $16,870. construct a 95% confidence interval for the population mean income of all psychologists with masters degrees. 7. you are working for a candidate in an election who has been regularly polling at 63% of the population in her favor. you need to check the poll numbers again, with a 90% confidence level and allowable nnargin of error of no rnore than 5%. what is the minimum sarnple size for your survey?