Based on these SMRs alone, it is possible to conclude that: a. The number of deaths from lung cancer in carpenters in 1949–1960 was greater than the number of deaths from lung cancer in bricklayers during the same period b. The proportionate mortality from lung cancer in bricklayers in 1949–1960 was greater than the proportionate mortality from lung cancer in the same occupational group in 1968–1979 c. The age-adjusted rate of death from lung cancer in bricklayers was greater in 1949– 1960 than it was in 1968–1979 d. The rate of death from lung cancer in carpenters in 1968–1979 was greater than would have been expected for a group of men of similar ages in all occupations e. The proportionate mortality rate from lung cancer in carpenters in 1968–1979 was 1.35 times greater than would have been expected for a group of men of similar

d. The rate of death from lung cancer in carpenters in 1968–1979 was greater than would have been expected for a group of men of similar ages in all occupations

Explanation:

SMRs - Standardized mortality ratios are useful for measuring whether a population, made-up of workers in a certain industry, has higher mortality than what would be expected if the population had the same mortality rate as those in the general population.

SMRs = (observed number of deaths) / (expected number of deaths.)

This tool is used as an indirect method to adjust age expectation.

To draw inferences, when the ratio of SMRs is greater than 1 (or 100 when multiplied by this amount to remove the decimal).

This shows that the occupational demographic grouping has a higher mortality rate than what would be expected for a similar group of people of differing ages who are representative of a series of occupations, not just carpentry.

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.