The following data represent the number of playground injuries occurring among children aged 5 to 9 years over a 3-month period in 12 playgrounds in and around the neighborhoods of Boston. Playground injuries include fractures, internal injuries, lacerations, and dislocations. The question of interest is whether there are differences in the numbers of injuries at playgrounds in various locations. The data below represent the numbers of injuries recorded at four randomly selected playgrounds located on school properties, at day-care centers, and in residential neighborhoods.
School properties 39 51 42 29
Day-care centers 28 25 30 15
Residential Neighborhoods 18 16 25 22
Run the appropriate test at a 5% level of significance.
a)What is the p-value obtained from this test?
b) What is the value for the number of degrees of freedom?
c) What is the value of the Kruskal-Wallis test statistic?