The z-score value shows how often standard deviations were away from the earth. If it is 0, it is on average. The positive Z sign indicates that perhaps the raw mark is greater than the average. While z-score is equivalent to +1, for example, it is a standard deviation of 1 above average. This can be used for implementing series and also for comparing the trend of mortality among various individuals or between various periods and by using the z score we find the curve length, that's why it is correct.
