Karl Pearson's correlation coefficient 'r' is a normalized metric of linear association mathematically bounded strictly within the range [-1, +1].

• 0 and 1: Range for the coefficient of determination (r²) or probability, not correlation coefficient 'r'.
• 1 and 1: By Cauchy-Schwarz inequality, Pearson's 'r' always lies between -1 (perfect negative correlation) and +1 (perfect positive correlation).
• 1 and 0: Applies only to strictly negative relationships.
• None of the above: Incorrect.

• The Coefficient of Variation (CV) was introduced by Karl Pearson as a relative measure of dispersion, independent of units of measurement.
• It is defined as the standard deviation (\sigma) expressed as a percentage of the arithmetic mean (\bar{X}):
  $$\text{CV (\%)} = \left(\frac{\text{Standard Deviation}}{\text{Mean}}\right) \times 100 = \left(\frac{\sigma}{\bar{X}}\right) \times 100$$
• In agricultural field experiments, CV% is an essential test of precision and experimental error; a lower CV indicates greater experimental reliability and homogeneity.
• gives the coefficient of variation as a fraction rather than a percentage (CV%).