Inferential testing (A-level only)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

Question 37

An environmental scientist is investigating the relationship between daily mean windspeed ( $w$ knots) and daily mean temperature ( $t$ $∘C{}^\circ\text{C}$ ). A random sample of $n = 30$ days from a weather database yielded a calculated product moment correlation coefficient of $r = - 0.382$ .

State whether this calculated value of $r$ is significant at the $0.05$ level for a two-tailed test. Explain your answer using Table 1 below.

Table 1 – Critical values for the Product Moment Correlation Coefficient ( $r$ )

$n$	Significance Level (Two-Tailed)
	0.10	0.05	0.01
28	0.3172	0.3739	0.4785
29	0.3115	0.3673	0.4705
30	0.3061	0.3610	0.4629
31	0.3009	0.3550	0.4556
32	0.2960	0.3494	0.4487

Table values are for a two-tailed test. To achieve significance, the magnitude (absolute value) of the calculated correlation coefficient must be greater than or equal to the table value.

[3]

State whether this calculated value of $r$ is significant at the $0.05$ level for a two-tailed test. Explain your answer using Table 1 below.

Table 1 – Critical values for the Product Moment Correlation Coefficient ( $r$ )

$n$	Significance Level (Two-Tailed)
	0.10	0.05	0.01
28	0.3172	0.3739	0.4785
29	0.3115	0.3673	0.4705
30	0.3061	0.3610	0.4629
31	0.3009	0.3550	0.4556
32	0.2960	0.3494	0.4487

Table values are for a two-tailed test. To achieve significance, the magnitude (absolute value) of the calculated correlation coefficient must be greater than or equal to the table value.

Inferential testing (A-level only)

Question 37

Markscheme

Inferential testing (A-level only)

Question 37

Markscheme

Inferential testing (A-level only)

Question 37

Inferential testing (A-level only) Questions

Inferential testing (A-level only)

Question 37

Inferential testing (A-level only) Questions