Influenza occurs on an annual basis in the United States, with case counts generally peaking during the colder months of the year. In 2011, the approximate influenza case count in the US was 9,000,000. The population of the US in 2011 was approximately 300,000,000. It is estimated that 30% of the US population either was immunized with vaccine or possessed natural immunity to 2011's flu strain. Nearly 45,000 people died from influenza in the US during 2011's "flu season." The total number of deaths in the US that year from all causes was 3,000,000. What was the proportional mortality ratio for influenza in 2011?

Given information is,

Total influenza case count in the US was 9000000.

Total Population of US is 300000000.

Total number of deaths in the US from all causes = D = 3000000

The number of deaths from as specific virus = The number of death by influenza virus = A = 45000.

We have to find the proportional mortality ratio for influenza in 2011.

Formula:

Proportional Mortality Ratio = (Number of deaths from Influenza virus) * 100 / (Total number of deaths in the Population)

That is,

Proportional Mortality Ratio = A/D*100

Now plugging the values = (45000) * 100 / 3000000

=4500000 / 3000000

= 1.5 %

Out of 100 people death from all causes there is 15 people who died from the influenza virus.