Answer:
a) Lower limit range = 119.7 ≈ 120
b) Upper limit range = 136.8 ≈ 137
Step-by-step explanation:
Given:
a) Lower limit range =
Therefore,
For the given person of age 43 years old
substituting the value of age in the above equation, we get
Lower limit range =
or
Lower limit range = 119.7 ≈ 120 beats per minute
b) The upper limit range = 
Therefore,
For the given person of age 43 years old
substituting the value of age in the above equation, we get
Upper limit range = 
or
Upper limit range = 
or
Upper limit range = 136.8 ≈ 137 beats per minute