Researchers Wanted to Compare the Effectiveness of a Water Softener

Essay

Researchers wanted to compare the effectiveness of a water softener used with a filtering process with a water softener used without filtering.Ninety locations were randomly divided into two groups of equal size.Group A locations used a water softener and the filtering process,while group B used only the water softener.At the end of three months,the water was tested at each location for its level of softness.(Water softness was measured on a scale of 1 to 5,with 5 being the softest water. )The results were as follows.
Refer to the sample data to test whether there is a difference between the two types of treatments.