I believe the average could be around 4.0 though 4.9 or around 5.0 through 6.0 :)
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When you excersise, your target heart rate should be between 25% to 70% of your maximum heart rate. Your target heart rate r at 70% can be determined by the formula r=0.7(220-a) where a represents your age in years. Solve the formula for a.</span>
