Answer:
Explanation:
The bone density scores that can be used as cut off values separating the lowest 12% and the highest 12% depend on the specific reference population being used. Different reference populations may have different mean bone density scores and different standard deviations, leading to different cut off values. Generally, bone density scores are reported as T-scores, which are calculated as the number of standard deviations a person's bone density score is from the mean bone density score of a reference population.
In general, a T-score of -2.5 or lower is used as the cut off value indicating osteoporosis, which is a condition of low bone density that increases the risk of bone fractures. However, this cut off value is based on the World Health Organization's reference population, which consists of young adult women. For men and for other reference populations, different cut off values may be used.
To determine the specific bone density scores that correspond to the lowest 12% and the highest 12% of a reference population, the mean and standard deviation of the population would need to be known. The z-scores corresponding to the lowest 12% and the highest 12% could then be calculated using the standard normal distribution, and these z-scores could be converted to T-scores using the mean and standard deviation of the reference population.