1. COEFFICIENT OF CORRELATION “r” Among quantities X i and Y i, both of them affected by the respective standard errors  Xi and  Yi. X Y  Xi  Yi ii X - Variance Y - Variance XY – Co-variance

2. Is r not equal to zero (statistically significant)? t TEST (N-2) degrees of freedom

3. RATIO OF CORRELATION “  ” 1 2 3 5 7 8 9 13 16 20 0 1 3 9 12 15 14 16 18 25 X Y n 1 = 3 elements n 2 = 3 elements n 3 = 4 elements k = 3 groups

4. Is  2 not equal to zero (statistically significant)? t TEST (N-2) degrees of freedom

5. ARE “r” and “  2 ” statistically equal or not? F TEST 1 = (N-2); 2 = (N – k) degrees of freedom

6. LINEAR CORRELATION r = 0.959 t r (22) = 15.89  = 0.973 t  (22) = 19.82 F(6, 16) = 1.36 m = 0.978 q = 1.547

7. UN CORRELATION r = 0.137 t r (22) = 0.65  = 0.423 t  (22) = 2.23 F(6, 16) = 0.641 m = 0.1 q = 20.1

8. NOT LINEAR CORRELATION r = 0.932 t r (22) = 12.1  = 0.985 t  (22) = 26.9 F(6, 16) = 9.15 m = 1.59 q = 1.1

9. REFERENCES 1.Amandola G., Terreni, V. Analisi Chimica Strumentale e Tecnica. V Ed., Masson Italia Editori, Milano 1986, pag. 587 – 596.