Suppose you find a restriction in your study of IQ scores and school achievement at a selective private school. Restricting the range is likely to do what to the correlation coefficient?
a. Increase the size
b. Underestimate the strength
c. Have no effect
d. Change the sign
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It's confusing at first because it gives you two scenarios - one when there is a ...
The correlation coefficient is given. The underestimate of strengths are given.