Heart corelation

Question 1

All the volunteers who took part in investigation C were aged between 40 and 50 years old. Explain how choosing volunteers of a similar age improved this investigation.

Answer 1

Age affects heart disease / age affects how alcohol affects the body;

Accept age affects results

Accept ‘removes confounding variable’

Accept ’controlling a variable’

Question 2

The way the student recorded her pulse produced pulse rates per minute with even numbers. Other than by chance, suggest why.

Answer 2

Pulse counted for 15/30 seconds;

2. Beats counted were multiplied by 2 or 4;