An environmental scientist conducted a study using a Wilcoxon Signed-Ranks test to investigate whether there is a significant difference in air particulate matter ( $PM2.5\text{PM}_{2.5}$ ) levels after a city-wide 'Car-Free Sunday' compared to the previous Sunday.

The Wilcoxon test yielded an observed (calculated) value of $T = 7$ for $N = 10$ monitoring stations.

Critical values of $T$ for a one-tailed test where $N = 10$

Significance Level	0.05	0.025	0.01
Critical value	10	8	5

Using the critical values table above, explain whether the researcher has found a significant difference or not.

The Wilcoxon test yielded an observed (calculated) value of $T = 7$ for $N = 10$ monitoring stations.

Critical values of $T$ for a one-tailed test where $N = 10$

Significance Level	0.05	0.025	0.01
Critical value	10	8	5

Using the critical values table above, explain whether the researcher has found a significant difference or not.

Data recording, analysis and presentation

Question 125

Critical values of $T$ for a one-tailed test where $N = 10$

Markscheme

Data recording, analysis and presentation

Question 125

Critical values of $T$ for a one-tailed test where $N = 10$

Markscheme

Data recording, analysis and presentation

Question 125

Critical values of TTT for a one-tailed test where N=10N = 10N=10

Data recording, analysis and presentation Questions

Data recording, analysis and presentation

Question 125

Critical values of TTT for a one-tailed test where N=10N = 10N=10

Data recording, analysis and presentation Questions

Critical values of $T$ for a one-tailed test where $N = 10$

Critical values of $T$ for a one-tailed test where $N = 10$