17. Zero correlation is seen when :
(A) Two variables are completely
dependent
(B) Two variables are partly dependent
(C) When two variables are completely
independent
(D) When two variables are negatively
correlated
Answers
Answer:
(a).Complete mutual dependence of random variables. A random variable Y will be said to be completely dependent on a random variable X if Y takes only one value for each value of X with probability one.
(b) In probability theory and statistics, partial correlation measures the degree of association between two random variables, with the effect of a set of controlling random variables removed. If we are interested in finding to what extent there is a numerical relationship between two variables of interest, using their correlation coefficient will give misleading results if there is another, confounding, variable that is numerically related to both variables of interest.
(c) You can tell if two random variables are independent by looking at their individual probabilities. If those probabilities don't change when the events meet, then those variables are independent. Another way of saying this is that if the two variables are correlated, then they are not independent.
(d) Negative correlation is a relationship between two variables in which one variable increases as the other decreases, and vice versa.