The rate of perceived exertion (RPE ) scale runs from 0 to 20 and is approximately proportional to a person's heart rate. If an RPE rank of 20 corresponds to a person's maximum heart rate of 20 beats per minute (BPM ). what RPE rank corresponds to the person's resting heart rate of 70 BPM? Round to the nearest integer. square

To find the RPE rank that corresponds to a resting heart rate of 70 BPM, we can use the proportionality between RPE and heart rate. Given that an RPE rank of 20 corresponds to a maximum heart rate of 20 BPM, we can set up a proportion to find the corresponding RPE for 70 BPM.<br /><br />Let \( x \) be the RPE rank that corresponds to 70 BPM. We can set up the following proportion:<br /><br />\[<br />\frac{70 \text{ BPM}}{x} = \frac{20 \text{ BPM}}{20}<br />\]<br /><br />Solving for \( x \):<br /><br />\[<br />70 \times 20 = 20 \times x<br />\]<br /><br />\[<br />1400 = 20x<br />\]<br /><br />\[<br />x = \frac{1400}{20}<br />\]<br /><br />\[<br />x = 70<br />\]<br /><br />Therefore, the RPE rank that corresponds to a resting heart rate of 70 BPM is \( \boxed{70} \).