Based on the data of air pollution in New York in 2019, the Environmental Protection Agency (EPA) decided to publish a new stricter regulation effective in January 2020 to reduce hydrocarbon pollution. EPA wants to evaluate whether the new regulation makes significant differences in reducing pollution. EPA collects data of monthly hydrocarbon pollution level as follows:

Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
2019	7.3	6.0	5.4	5.9	3.9	5.7	6.9	7.6	6.3	5.8	5.1	5.9
2020	5.3	6.1	5.6	5.7	3.7	4.7	6.1	7.2	6.4	5.7	4.9	5.8

a. What statistical method can be applied for this study? Explain your answer b. What is the hypothesis of the study? c. At a 5% significance level, is the performance between the two sample groups significantly different?

Please if can, can you provide it in excel