CHI-SQUARED TEST:

For the entire study period (1940-1986), the overall expected larynx cancers, based on US., New York, and Connecticut rates, respectively, were 3.44, 2.94, and 3.89. Adjusting these expected figures upward 15% to account for excess smoking among the cohort, the expected larynx cancers were 3.92, 3.35, and 4.43, respectively, leading to standardized rate ratios of 2.30, 2.70, and 2.04, respectively.<>

After considering the above, try and answer the following questions:

1. QUESTION 10. Calculate the chi-square test of significance for the standardized rate ratio using U.S. rates as the reference rates.
   Is the rate ratio significantly different than 1.0?
   Calculate the test-based confidence intervals, or range of plausible values, for this same rate ratio.