Figure 2 illustrates a normal distribution of test scores with a mean of 100 and a standard deviation of 15. The standard deviation is an indication of the variability of scores in a population (Mather & Jaffe, 2002).nderstanding Standard Scores. The major purpose of standard scores is to place scores for any individual on any variable having any mean and standard deviation on the same standard scale so that comparisons can be made.
Note: True symptoms of PMS do not begin until after Day 13, any symptoms you experience earlier in your cycle may have another cause. However, you should still include any symptoms you experience on Days 1 to 13 on your menstrual cycle calendar.
PMS affects girls a little bit before their period starts and gets better when they actually have their period, while period cramps usually start as soon as girls get their period. Period cramps normally start right before you get your period and are at their worst about a day after you first start feeling sore.You might get cramps more than your mum or older sister as they tend to affect younger women and girls more and get less painful with age.MS affects girls a little bit before their period starts and gets better when they actually have their period, while period cramps usually start as soon as girls get their period. Period cramps normally start right before you get your period and are at their worst about a day after you first start feeling sore.