1. Why is a z score a standard score? Why can standard scores be used to compare scores from different distributions?

A z score is a standard score because it measures the magnitude in terms of the number of standard deviations that a score may be away from the mean.
The comparison is possible because there are no units involved. Besides, there is no scale involved either. This way comparisons may be made. ย

1. For the following set of scores, fill in the cells. The mean is 74.13 and the standard deviation is 9.98.
1. Questions 3a through 3d are based on a distribution of scores with and the standard deviation = 6.38. Draw a small picture to help you see what is required.
2. What is the probability of a score falling between a raw score of 70 and 80?
3. What is the probability of a score falling above a raw score of 80?
4. What is the probability of a score falling between a raw score of 81 and 83?
5. What is the probability of a score falling below a raw score of 63?
6. Jake needs to score in the top 10% in order to earn a physical fitness certificate. The class mean is 78 and the standard deviation is 5.5. What raw score does he need?