Question

When garbage is thrown into recycle bins, the contamination makes recycle handling very expensive. The government of a large city launched an extensive education campaign to reduce contamination. To access the success of the campaign, a researcher compared the data for each of 12 collection routes before and after, with the results given below. Is this sufficient evidence at the 10% significance level to conclude that there was a reduction after the campaign? Do not round intermediate calculations.

	Before	After
n	12	12
Mean contamination per person (kg)	22.1	18.9
Sample standard deviation	4.89	3.64

Answer 1