The Miller Analogies Test (MAT) scaled scores range from 200 to 600 with a mean of approximately 400, so any score above 400 is good because it's in the upper 50th percentile for all test takers. A score of 425 is about the 69th percentile for all test takers.
The MAT provides percentile scores by major in addition to the scaled score on score reports. These percentiles do not match the percentiles for all test takers. For example, the standard deviation for the MAT scores is 25, so test takers scoring 450 are at the 84th percentile for all test takers, but may be higher or lower for a person with a particular major.