This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Biostatistics, Subject name: Social & Preventive Medicine
correlation coefficient tends to lie between - 
Select and explain. 
A. Zero to - 1.0, B. 0, C. +1.0 to zero, D. +2.0 to -2.0
B: 0
Answer: B: 0 
Explanation: Ref:Parks 23rd edition pg 852 In order to find out whether there is significant association or not between the two variables , coefficient or Corelation is calculated . r lies between -1 and +1 r near -1 : indicates strong negative correlation . r = 0 : indicates no association r near +1: indicates strong positive correlation. Note: correlation does not necessarily prove causation .