In an experiment on the effect of caffeine on time to complete a manual task, Pa

ID: 3205725 • Letter: I

Question

In an experiment on the effect of caffeine on time to complete a manual task, Paolo has three treatments-0 mg, 150 mg, and 300 mg of caffeine. He assigns an equal number of 13 participants to each of his 3 conditions (39 total people). He calculates his sigma X^-2_tot = 95, and sigma((sigma X in column)^2/n in column) = 70. Complete the following source table: What should his statistical decision be? What should he conclude about the effect of caffeine on time to complete the task? What post hoc test would you do to determine which levels are different from one another?

Explanation / Answer

Result:

N=39

Total sum of square = 95-50^2/39 =30.8974

Between group sum of square= 70-50^2/39 =5.8974

Error sum of squares = 30.89744-5.897436 =25

Source

Treatment

5.8974

2.9487

4.36

Error

0.6757

Total

30.8974

b).

critical value of F(2.37) at 0.05 level =3.25

calculated F=4.36 > 3.25 the table value.

Null hypothesis is rejected.

c).

we conclude that there is significant effect of caffeine on time to complete the test.

d).

Tukey-Kramer test may be used .