The mortality experience of 8146 male employees of a research engineering and metal fabrication plant in New York, was studied from 1946-1981. Potential workplace exposures included welding fumes, cutting oils, asbestos, organic solvents, and environmental ionizing radiation, as a result of waste disposal during the Manhattan project in World War II. Comparisons were made for specific causes of death between mortality rates in workers and U.S white male mortality rates from 1950-1978.

Suppose that 17 deaths from cirrhosis of the liver were observed among workers who were hired prior to 1946 and who had worked in the plant for 10 or more years, whereas 6.3 were expected based on US white-male mortality rates.

Perform a significance test to assess whether there is an association between mortality from cirrhosis of the liver and duration of employment in the group hired after 1945. Report a p- value.