A researcher is interested in comparing the rates of mortality due to motor-vehicle accidents in two

A researcher is interested in comparing the
rates of mortality due to motor-vehicle accidents in two communities after
adjusting for age. The number of person-years of follow-up for specific age
categories and the number of fatalities observed for communities A and Β
are given in the next table.

(a) Combine the two communities to derive a standard
population. Then, use the direct method of standardization to compare the
motor-vehicle mortality rates in the two populations. A spreadsheet program may
be used to make calculations easier.

(b) Test the null hypothesis that the
direct adjusted rates are equal using a chi-square test and a = 0.05.