ONE-SAMPLE T-TEST

One-Sample T-Test



One-Sample T-Test

Thirty anorexic girls were treated with cognitive behavioral therapy (CBT). These values were measured before and after the treatment. The weight gains (positive values) and weight losses (negative values) are given below. A gain of more than zero pounds would confirm whether the treatment worked. Did the group gain more than zero pounds?

Data:

1.7

0.7

-0.1

-0.7

-3.5

14.9

3.5

17.1

-7.6

1.6

11.7

6.1

1.1

-4.0

20.9

-9.1

2.1

-1.4

1.4

-0.3

-3.7

-0.8

2.4

12.6

1.9

3.9

0.1

15.4

-0.7

0

Descriptive Statistics

Mean = 2.91

S.D = 7.20

Data:

n = 30

µ = 0

s = 7.20

X-bar = 2.91

(1) Formulate the hypotheses:

H0: µ = 0H1: µ > 0

(2) Decide the test statistic and the level of significance:

t (Right-tailed), a = 0.05

Critical t- score = 1.6991

(3) The Decision Rule:

Reject H0 ...