Tool workers are subject to work-related injuries. One disorder, caused by strains to the hands and wrists, is called carpal tunnel syndrome. It...

Tool workers are subject to work-related injuries. One disorder, caused by strains to the hands and wrists, is called carpal tunnel syndrome. It strikes as many as 23,000 workers per year. It is estimated that the average cost of this disorder to employers and insurers is ap- proximately $30,000 per injured worker. Suppose these costs are normally distributed, with a standard deviation of $9,000.

What proportion of the costs are greater than $45,000?