A business owner would like to know if the new marketing strategy improves their sales. They recorded their average income before and after they change their strategy. Before, they have an average income per month of $ 100,098 with a standard deviation of $ 64, 090. Now, they computed their monthly average of $ 102,190 with a standard deviation of $ 55, 976.Use n= 30 and Test the claim that there is a significant increase of their income due to their new marketing strategy using 0.05 level of significance.