Analysis of Infection Risk in Hospitals: A Multiple Regression ApproachUsing Stepwise and Subset Regression MethodsFor this assignment use the data setsenic.xlsx.This data set consists of a random sample of 113hospitals. The objective is to study the infection risk and what factors influence it.The variables from thedata set are:Variable NameDescriptionIdentification number1-113Length of stayAverage length of stay in hospital (in days)AgeAverage age of patients (in years)Infection riskAverage estimated probability of acquiring infection in hospital (inpercent)Routing culturing ratioRatio of number of cultures performed tonumber of patientswithout signs or symptoms of pneumonia, times 100Routine chest X-rayratioRatio of number of X-rays performed to number of patients withoutsigns or symptoms of pneumonia, times 100Number of bedsAverage number of beds in hospitalMedical schoolaffiliation0 = Yes, 1 = NoAverage daily censusAverage number of patients in hospital per dayNumber of nursesAverage number of full-time licensed practical nursesAvailable facilities andservicesPercent of 35 potentialfacilities and services that are provided bythe hospitalThe goal is to fit the best multiple regression model to the response (infection risk).Do an analysis usingthefirst 108 observations.Use the stepwise regression method to see which model is the best. Repeat using subset regression. Dothey agree?Are there any outliers in the data? Look forx-outliers,y-outliers, and high-influence points.Come up with one model that you think best describes the data and can be used for future predictions.Showthe residual plot for this one.Does the model seem appropriate?Use this model to predict (using prediction interval)yfor the last 5 observations of the data and see ifthe model is doing well.Preview Mode
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