The percentage of hearing loss experienced by people throughout their adult years can be modeled by the equation
y=0.0086x2 – 0.4267x + 6.6434, with 18 5x 584,
where y represents the percent of hearing loss and x is the age of a person.
1. By the age of 18, what percent of hearing loss can a person experience?
2. Find the percent range of hearing loss for the 30–60 year age group.
3. Find the percent range of hearing loss for the 60–84 year age group.
4. Find the age group where the percent of hearing loss is less than 5%.
5. Find the age group where the percent of hearing loss is greater than 25%.
6. Find the age group where the percent of hearing loss is greater than 15%, but less
than 30%.
7. Sketch a graph of the equation. Use your graph to check your answers for Exercises
1-6.