An insurance company would like to estimate the average amount

claimed by its policyholders over the past year. A random sample of 300 policyholders

was chosen, whose observed sample mean was $739.98 and whose sample

standard deviation was $312.70.

The company's primary concern is to avoid underestimating the average amount claimed by its policyholders. Determine a value b so that the insurance company is 95% confident that the average amount claimed by its policyholders is b or less.