(b) Does the conclusion that a regression relation exists imply that the software quality engineer need not screen the independent variables and can just use them all? If a regression relation had not existed, what would this imply about screening the independent variables?

2. A software quality engineer wants to develop a regression model for predicting the number of faults in program (y). S/He decided that four software complexity metrics are potentially useful as independent variables, namely program size in lines of code in program (x) and excecutable lines of code (2), program control flow measured in terms of the number of branches (r3) and the number of tokens in program x4). Data were collected on a set of 24 programs from a distributed application in a data communication software system. The ANOVA table for the model yi = A-+Alli +AT2i +BuT3i + ?4E4i + Ei was found to be as follows: Source of Variation dfSS MS Model Error Total 4 5409.99 19 16.35 23 5426.34 2. A software quality engineer wants to develop a regression model for predicting the number of faults in program (y). S/He decided that four software complexity metrics are potentially useful as independent variables, namely program size in lines of code in program (x) and excecutable lines of code (2), program control flow measured in terms of the number of branches (r3) and the number of tokens in program x4). Data were collected on a set of 24 programs from a distributed application in a data communication software system. The ANOVA table for the model yi = A-+Alli +AT2i +BuT3i + ?4E4i + Ei was found to be as follows: Source of Variation dfSS MS Model Error Total 4 5409.99 19 16.35 23 5426.34