Families USA, a monthly magazine that discusses issues related to health and health costs, surveyed 21 of its subscribers. It found that the annual health insurance premiums for a family with coverage through an employer averaged $10,650. The standard deviation of the sample was $1,025. (Use t Distribution Table.)

1. Based on this sample information, develop a 99% confidence interval for the population mean yearly premium. (Round your answers to the nearest whole dollar amount.)
2. How large a sample is needed to find the population mean within $235 at 90% confidence? (Round up your answer to the next whole number.)