Page 17 - Statistics presented by Dr. Sara Ismail Aborass

9/8/2023

The sign of r denotes the
nature of association

while the value of r denotes
the strength of association.

Linear relation r approaches
1(+or-) perfect linear

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The value of r ranges between ( -1) and ( +1)
The value of r denotes the strength of linear association as

illustrated.
As the value approaches the unity, we get a strong linear
Notice that we need a good linear correlation to construct

our (regression) calibration curve or plot for the
estimation of the unknown concentration.

How to compute the simple correlation coefficient (r)

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