a 14 year old boy has a resting heart rate of 76. using lower and upper reserve training percents of 50 and 85 what is his target heart range?

110 to 180

130 to 206

141 to 186

144 to 206

To calculate the target heart range for a 14-year-old boy with a resting heart rate of 76, you can use the formula:

Target Heart Range = (Resting Heart Rate + (Lower Reserve Percent × (Maximum Heart Rate - Resting Heart Rate))) to (Resting Heart Rate + (Upper Reserve Percent × (Maximum Heart Rate - Resting Heart Rate)))

Here are the steps to calculate the target heart range:

1. Calculate the Maximum Heart Rate (MHR):
MHR = 220 - Age
In this case, the boy is 14 years old, so the MHR = 220 - 14 = 206.

2. Calculate the target heart range using the given lower and upper reserve training percentages:
Lower reserve percent = 50% = 0.50
Upper reserve percent = 85% = 0.85

Target Heart Range = (76 + (0.50 × (206 - 76))) to (76 + (0.85 × (206 - 76)))

Calculate the lower limit:
Target Heart Range (Lower Limit) = 76 + (0.50 × (206 - 76)) = 76 + (0.50 × 130) = 76 + 65 = 141

Calculate the upper limit:
Target Heart Range (Upper Limit) = 76 + (0.85 × (206 - 76)) = 76 + (0.85 × 130) = 76 + 110.5 = 186.5
Rounded to the nearest whole number: 187

Therefore, the target heart range for the 14-year-old boy would be 141 to 187 (using whole numbers). So the closest option is "141 to 186".