Dr. Sterling’s investigation on weekly screen usage (in hours) and sleep quality index scores among 8 undergraduate students yielded the data shown in Table 1.

Complete Table 2 and calculate Spearman’s rank correlation coefficient ( $r_s$ ) between the weekly screen usage and the sleep quality index score.

Table 1: Raw scores for screen usage and sleep quality index

Student	Screen usage (hours per week)	Sleep quality index
A	14	42
B	18	35
C	18	38
D	22	28
E	25	28
F	28	20
G	35	15
H	12	45

Table 2: Step-by-step ranking and calculation

Screen usage (hours per week)	Rank 1	Sleep quality index	Rank 2	$d$
14	2	42	7
18	3.5	35	5
18	3.5	38	6
22	5	28	3.5
25	6	28	3.5
28	7	20	2
35	8	15	1
12	1	45	8
				Total:

Dr. Sterling’s investigation on weekly screen usage (in hours) and sleep quality index scores among 8 undergraduate students yielded the data shown in Table 1.

Complete Table 2 and calculate Spearman’s rank correlation coefficient ( $r_s$ ) between the weekly screen usage and the sleep quality index score.

Table 1: Raw scores for screen usage and sleep quality index

Student	Screen usage (hours per week)	Sleep quality index
A	14	42
B	18	35
C	18	38
D	22	28
E	25	28
F	28	20
G	35	15
H	12	45

Table 2: Step-by-step ranking and calculation

Screen usage (hours per week)	Rank 1	Sleep quality index	Rank 2	$d$
14	2	42	7
18	3.5	35	5
18	3.5	38	6
22	5	28	3.5
25	6	28	3.5
28	7	20	2
35	8	15	1
12	1	45	8
				Total:

Methods

Question 198

Table 1: Raw scores for screen usage and sleep quality index

Table 2: Step-by-step ranking and calculation

Markscheme

Methods

Question 198

Table 1: Raw scores for screen usage and sleep quality index

Table 2: Step-by-step ranking and calculation

Markscheme

Methods

Question 198

Table 1: Raw scores for screen usage and sleep quality index

Table 2: Step-by-step ranking and calculation

Methods Questions

Methods

Question 198

Table 1: Raw scores for screen usage and sleep quality index

Table 2: Step-by-step ranking and calculation

Methods Questions