An insurance company employs agents on a commission basis. It claims that, in their first year, agents will earn a mean commission of at least $40,000 and that the population standard deviation is no...

An insurance company employs agents on a commission basis. It claims that, in their first year, agents will earn a mean commission of at least $40,000 and that the population standard deviation is no more than $6,000. A random sample of nine agents found for commission in the first year,

measured in thousands of dollars. The population distribution can be assumed to be normal. Test, at the 10% level, the null hypothesis that the population standard deviation is at most $6,000.