Question

within groups 380.263 9.054
total 475.970
the spss output for the contrast \\( \psi \\), which compares the color brightness of
fuji film to the average of the other two brands, is given below.

contrast tests

	value of contrasts	std. error	t	sig. (2 - tailed)

what is the \\( p \\)-value for testing if the color brightness of fuji film is significantly
higher than the average of the other two brands?

• \\( p \\)-value = 0.004, because for performing a one - sided test we have to divide the

reported \\( p \\)-value by 2.

• \\( p \\)-value = 0.008, because that is the \\( p \\)-value reported in the output.

Explanation:

Step1: Identify test type

The question is one-sided (Fuji > average of others).

Step2: Check SPSS output

SPSS gives 2-tailed Sig. = 0.008.

Step3: Calculate 1-tailed p-value

Divide 2-tailed p-value by 2: $\frac{0.008}{2} = 0.004$.

Answer:

P-value = 0.004, because for performing a one-sided test we have to divide the reported P-value by 2.