1. What is the motivation behind constructing multivariate control charts? What advantages do they have over control charts for individual characteristics?
2. Lung congestion may occur in illness among infants. However, it is not easily verifiable without radiography. To monitor an ill infant to predict whether lung opacity will occur on a radiograph, data are kept on age, respiration rate, heart rate, temperature, and pulse oximetry. Target values for each variable are identified. What control chart should you use in this context?