- ### Homework Question 2 335 The nwtco daset in the survival package include s a study predicting survival based on tumor histology (tissue structure). data(nwtco, package="survival") head(nwtco) - The variable *edrel gives the time to relapse. {r} hist(nwtcoSedrel) summaryCas.factor(nwtcosinstit)) summaryCas.factor(nwtcoshistol) summarycas.factor (nwtcosstage)) Construct a cross-validation where you compare how well *instit* predicts time to relapse compared to "histol*. These represent the histology from the local institution versus the central lab. In both cases include age and stage as predictors. Stage should be included as factor variable. - ### Homework Question 2 335 The nwtco daset in the survival package include s a study predicting survival based on tumor histology (tissue structure). data(nwtco, package="survival") head(nwtco) - The variable *edrel gives the time to relapse. {r} hist(nwtcoSedrel) summaryCas.factor(nwtcosinstit)) summaryCas.factor(nwtcoshistol) summarycas.factor (nwtcosstage)) Construct a cross-validation where you compare how well *instit* predicts time to relapse compared to "histol*. These represent the histology from the local institution versus the central lab. In both cases include age and stage as predictors. Stage should be included as factor variable