Researchers Wanted to Compare the Effectiveness of a Water Softener

question 13

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.

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Definitions:

Kruskal-Wallis Test

A non-parametric test that is utilized to ascertain if statistically meaningful differences exist among two or more categories of an independent variable concerning a continuous or ordinal dependent variable.

Significance Level

The probability of rejecting the null hypothesis in a statistical test when it is actually true, typically denoted by alpha.

Two-Independent Sample T-Test

A statistical test used to compare the means of two independent groups to determine if there is a statistically significant difference between them.

Wilcoxon Signed Rank Test

The Wilcoxon signed rank test is a nonparametric statistical test used to compare the median of two related samples to determine if there are significant differences between them.