t test for dependent samples
TRANSCRIPT
t-test for dependent samples
Mike Arieh P. Medina
The problem
• Is sedimentation significantly higher on a rainy day than on ordinary days in River Z at 0.001?
DatasetRegular Day Rainy Day d d2
16 32 -16 2563 22 -19 361
17 23 -6 363 13 -10 100
19 20 -1 115 29 -14 19624 11 13 16923 25 -2 43 13 -10 100
12 20 -8 6432 30 2 4
∑d = -71 ∑d2 = 1291
N = 11
Formula
Calculation
t= -2.35df = N(number of pairs) – 1df = 11-1 = 10
Interpretation
• Accept Ho if tcomputed < ttabular
• Reject Ho if tcomputed > ttabular
• Accept H1 if tcomputed > ttabular
• Reject H1 if tcomputed < ttabular
