1. The ages in days of samples of accounts receivable from two supplier companies 1 and 2, both of which extend 30 days credit, are shown below:

1                                                                 2

15                    15                                            30                    40

15                    30                                            35                    40

20                    40                                            35                    45

25                    45                                             35                    45

35                    45                                            40                    50

Using means and standard deviations of the two sets of data, compare the profile of the ages of accounts receivable of the two companies.

2. What proportion of the scores in a normal distribution are higher than a T-score of 70?

3. What Z-score has 90% of the scores below it?

4.What deviation IQ score ranges would include 90% of the population?

5. Researchers study relations among personality variables and various behaviors. In this example, psychologists studied a sample of 104 adolescents high school students in Quezon City. The researchers assessed a personality variable called "agreeableness" using a standard personality questionnaire. This is a measure of how nice that person is to be around. The questions ask about how cheerful, stubborn, polite, bossy, and cooperative the person is. Each adolescent's average of those items is reported.

They also created a measure of behavior problems. The youths reported on various behaviors in the last six months, including cheating, swearing, stealing, and fighting. Each adolescent's sum of behavior problems is reported. 

This table shows a representative sample of 10 participants, but keep in mind that they had 104 adolescents in their sample.

Compute correlation coefficient.