Question

What is the sST for the data set (1, 5), (2, 8), (4, 14)?

14
42
25
9

Answer 1

42

Explanation:

SST = ∑ ( y − ¯ y ) ² (¯ y = mean of y values)

¯ y = (5+8+14)/3 = 27/3 = 9

∑ ( y − ¯ y ) ² = ( 5 − 9 ) ² + ( 8 − 9 ) ² + ( 14 −9 ) ²

= ( − 4 ) ² + ( − 1 ) ² + ( 5 ) ²

= 16 + 1 + 25

= 42