National Counselor Exam Practice Test 2025 – Comprehensive Study Resource

The percentile range that is most commonly recognized as encompassing average ability is from 16 to 84. This range reflects the distribution of scores in a normal distribution (bell curve) where approximately 68% of the population falls within one standard deviation of the mean. Specifically, in a standard normal distribution, a score at the 50th percentile represents the median, and scores at the 16th and 84th percentiles mark approximately one standard deviation below and above the mean, respectively. This captures the middle range of abilities, suggesting that individuals scoring within this range are considered to have average abilities relative to the population.

In contrast, the other ranges mentioned do not align with this understanding of average ability. For instance, the range from 0 to 50 encompasses below average scores, and the range from 50 to 75 indicates a score that is above the median and not truly reflective of the average. Meanwhile, the range from 75 to 100 represents higher abilities well above the average, which also does not fit the definition of average ability. Thus, the percentile range of 16 to 84 accurately encapsulates the average ability within the context of psychological testing and relevant assessments.