# Behavior Science, psychology homework help

Complete Parts A and B

# Part A

1. Why is a z score a standard score? Why can standard scores be used to compare scores from different distributions?
2. For the following set of scores, fill in the cells. The mean is 74.13 and the standard deviation is 9.98.
 Raw score Z score 68.0 ? ? –1.6 82.0 ? ? 1.8 69.0 ? ? –0.5 85.0 ? ? 1.7 72.0 ?
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 3a. What is the probability of a score falling between a raw score of 70 and 80? 3b. What is the probability of a score falling above a raw score of 80? 3c. What is the probability of a score falling between a raw score of 81 and 83? 3d. What is the probability of a score falling below a raw score of 63

# Part B

Complete the questions below. Be specific and provide examples when relevant.

Cite any sources consistent with APA guidelines.

 Question Answer What is the relationship between reliability and validity? How can a test be reliable but not valid? Can a test be valid but not reliable? Why or why not? How does understanding probability help you understand statistics? How could you use standard scores and the standard distribution to compare the reading scores of two students receiving special reading resource help and one student in a standard classroom who does not get special help? In a standard normal distribution: What does a z score of 1 represent? What percent of cases fall between the mean and one standard deviation above the mean? What percent fall between the mean and –1 to +1 standard deviations from the mean? What percent of scores will fall between –3 and +3 standard deviations under the normal curve? 