a. To find the best estimate for the percentage of people who were affected, we need to divide the affected people by the total population and multiply by 100%. Let's see:

The best estimate for the percentage of people who were affected is about 0.1%
b. To complete the statement, apply the proportion:

Solve for x:

Approximately 86 out of every 100,000 people in the United States were affected by the 1994 salmonella outbreak.