Question

A program to decrease littering was carried out in four cities in California’s Central Valley starting in August 2007. The amount of litter in the streets (average pounds of litter collected per block per day) was measured during July before the program started and then the next July, after the program had been in effect for a year. The results are as follows:

City	July 2007	July 2008
Fresno	9	2
Merced	10	4
Bakersfield	8	9
Stockton	9	1

1. Using the .01 significance level, was there a significant decrease in the amount of litter? Use the steps of hypothesis testing (15 pts). To get full credit you must state the null and alternative hypothesis in both words and symbols, and state your conclusion fully

Answer 1

Given:

A program to decrease littering was carried out in four cities in California’s Central Valley starting in August 2007.

The amount of litter in the streets (average pounds of litter collected per block per day) was measured during July before the program started and then the next July, after the program had been in effect for a year. The results are as follows:

City	July 2007, X	July 2008, Y	d = X-Y	d2
Fresno	9	2	7	49
Merced	10	4	6	36
Bakersfield	8	9	-1	1
Stockton	9	1	8	64
Total			d= 20	d2 = 150

Hypothesis test:

In word :

Ho : There a significant decrease in the amount of litter.

Ha : There a significant decrease in the amount of litter.

In symbol :

Ho : = 0

Ha : < 0

Conclusion : At 0.01 significance level, there is not a significant decrease in the amount of litter.