Question

The maximum heart rate of a person in normal health is related to the person's age by the equation $r=220-A$ where $r$ is the maximum heart rate in beats per minute and $A$ is the person's age in years. Some physiologists recommend that during physical activity a person should strive to increase his or her heart rate to at least $60 \%$ of the maximum heart rate for sedentary people and at most $90 \%$ of the maximum heart rate for highly fit people. Express as an interval the range of the target heart rate for a 20 -year-old.

          The maximum heart rate of a person in normal health is related to the person's age by the equation
$r=220-A$
where $r$ is the maximum heart rate in beats per minute and $A$ is the person's age in years. Some physiologists recommend that during physical activity a person should strive to increase his or her heart rate to at least $60 \%$ of the maximum heart rate for sedentary people and at most $90 \%$ of the maximum heart rate for highly fit people. Express as an interval the range of the target heart rate for a 20 -year-old.

Added by Kara G.

Calculus: Early Transcendentals

James Stewart 8th Edition

Instant Answer

Solved by Expert William Semus

12/30/2021

Step 1

Use the formula $ r = 220 - A $, where $ A $ is the age. Substitute $ A = 20 $ into the formula: \[ r = 220 - 20 = 200 \text{ beats per minute} \] Show more…

Show all steps

Thanks for your feedback!

The maximum heart rate of a person in normal health is related to the person's age by the equation $r=220-A$ where $r$ is the maximum heart rate in beats per minute and $A$ is the person's age in years. Some physiologists recommend that during physical activity a person should strive to increase his or her heart rate to at least $60 \%$ of the maximum heart rate for sedentary people and at most $90 \%$ of the maximum heart rate for highly fit people. Express as an interval the range of the target heart rate for a 20 -year-old.