Question

Psychopaths tend to be cold and calculated, often not worrying about others or consequences so they are typically not anxious. You are curious whether anxiety scores for people are associated with psychopathy scores. To test this you survey 12 undergraduate students on their anxiety level (0 to 100, higher mean more anxious) and their score on a standard psychopathy measure (0 to 40, higher score indicated a higher level of psychopathy). The data is as follows:

person	Anxiety	Psychopathy
1	75	5
2	50	15
3	27	20
4	60	10
5	5	19
6	5	21
7	6	15
8	71	3
9	2	30
10	9	17
11	3	12
12	10	18

1) If you consider both variables to be interval, what is the correlation between anxiety and psychopathy scores?

Answer 1

Solution:

We have to find  the correlation between anxiety and psychopathy scores.

where

thus

person	x: Anxiety	y: Psychopathy	x^2	y^2	xy
1	75	5	5625	25	375
2	50	15	2500	225	750
3	27	20	729	400	540
4	60	10	3600	100	600
5	5	19	25	361	95
6	5	21	25	441	105
7	6	15	36	225	90
8	71	3	5041	9	213
9	2	30	4	900	60
10	9	17	81	289	153
11	3	12	9	144	36
12	10	18	100	324	180
Totals

Thus

thus

Thus the correlation between anxiety and psychopathy scores is