how can a correlation measure aid the process of predictions

Prediction: Correlations can be used to help make predictions. If two variables have been known in the past to correlate, then we can assume they will continue to correlate in the future. We can use the value of one variable that is known now to predict the value that the other variable will take on in the future.

A positive correlation is one in which variables go up or down together, producing an uphill slope. ... Any type of correlation can be used to make a prediction. However, a correlation does not tell us about the underlying cause of a relationship.

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