Indicate whether or not the following statements regarding the correlation coeff
ID: 3228446 • Letter: I
Question
Indicate whether or not the following statements regarding the correlation coefficient r are True or False F/T An r value of +0.65 offers stronger proof of cause and effect than does an r value of -0.50. F/T An r = 0.0 implies there is absolutely no mathematical correlation between two variables. F/T An r value > 0.0 implies that Y increases as X decreases. F/T An r value > 0.0 always indicates significant correlation. F/T When comparing correlation between two variables, use averages rather than individual values. F/T If r > 0.5, it is permissible to extrapolate values of Y for values of X that are not in the data range of X. F/T Only positive values of r provide evidence of cause and effect.Explanation / Answer
a) An r value of 0.65 offers a stronger proof of cause and effect than does an r value of -0.5 because an r value of -0.5 has a modulus value of 0.5 which is lower than 0.65 and therefore a +0.65 correlation value has a greater cause and effect relationship than the -0.5 value.
therefore the given statement is true.
b) An r=0 means that there is no mathematical correlation between the 2 variables that is the covariance between the 2 variables is 0.
therefore the given statement is true.
c) An r value of > 0 implites that there is positive correlation between the variables and therefore it implies that Y increases as X increases.
therefore the given statement is false.
d) An r value of > 0 only means a positive correlation. It does not signify the strength of the relationship. The strength depends on the magnitude of the correlation. The correlation value of closer to 1 or -1 indicates significant correlation
therefore the given statement is false.