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.
The mean score is 60 out of 100 and the standard deviation (in other words, the variation in the scores) is 15 marks (see our statistical guides, Measures of Central Tendency and Standard Deviation, for more information about the mean and standard deviation).tandard Normal Distribution and Standard Score (z-score). 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).