The following data are from a hypothetical study on the effe

The following data are from a hypothetical study on the effects of age and time on scores on a test of reading comprehension. Compute the analysis of variance summary table.

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Solution

MINITAB is used

General Linear Model: score versus time, age

Method

Factor coding (-1, 0, +1)

Factor Information

Factor Type   Levels Values

time    Fixed       2 30, 60

age     Fixed       2 12, 16

Analysis of Variance

Source      DF Adj SS   Adj MS F-Value P-Value

time       1   793.8   793.80    18.77    0.001

age        1 2000.0 2000.00    47.28    0.000

time*age   1   336.2   336.20     7.95    0.012

Error       16   676.8    42.30

Total       19 3806.8

The time factor is significant, F=18.77, P=0.001 which is < 0.05

The age factor is significant, F=47.88, P=0.000 which is < 0.05

The time* age interaction factor is significant, F=7.95, P=0.012 which is < 0.05