Correlation:

I decided to check if there is a correlation between the number of outlets having > 15 ppb lead levels and the mean scale score for the subject of Mathematics for grades 3-8 in all those schools. The hypothesis was tested using Pearson’s Correlation Coefficient.
H0 :  There is no correlation between the number of outlets having > 15 ppb lead levels of the schools and the mean scale score in Mathematics for all grades of that school. Significance level alpha= 0.05
Ha:  There is a correlation between the number of outlets having > 15 ppb lead levels in the water of the schools and the mean scale score in Mathematics for all grades of that school.