The common symptoms of an overactive thyroid are weight loss, increased appetite, irritability, rapid heart rate and anxiety, according to the Office on Women's Health, whereas underactive thyroid symptoms include weight gain, cold sensitivity, fatigue, depression and muscle weakness.
Z-Scores Explained. A z-score is a score that falls somewhere within the standard normal distribution. Its counterpart on the standard distribution is the standard score. The standard normal distribution and z-score allow all the standardized scores to be weighed equally through a few calculations. z-score is a score that falls somewhere within the standard normal distribution. Its counterpart on the standard distribution is the standard score. The standard normal distribution and z-score allow all the standardized scores to be weighed equally through a few calculations.
As such, we can use something called the standard normal distribution and its related z-scores to answer these questions much more easily. When a frequency distribution is normally distributed, we can find out the probability of a score occurring by standardising the scores, known as standard scores (or z scores).