• Normal distribution is a probability distribution that plots all of its values in a symmetrical fashion and most of the results are situated around the probabilitys mean.• It is graphically represented by a symmetrical bell- shaped curve that known as the normal curve.
• The curve concentrated in the center and decreases on either side. This means that the data has less of a tendency to produce unusually extreme values, compared to some other distributions.• The bell shaped curve is symmetric. This tells you that the probability of deviations from the mean is comparable in either direction.
• The standard score is the distance of the score from the mean in terms of the standard deviations the observed value lies above or below the mean of the distributions.
• Frequencies of scores in distributions can be found using the normal curve. Several problems on the different fields can be solved by applying the normal curve.
Find the z- score of 80 z = - 1.33 = 0.4082 (tabular)