Take the family lung function data described in Appendix A and delete (label as missing) the height of the middle child for every family with ID divisible by 6, that is, families 6, 12, 18 etc.

(To find these, look for those IDs with ID/6=integer part of (ID/6).) Delete the FEV1 of the middle child for families with ID divisible by 10. Assume these data are missing completely at random. Try the various imputation methods suggested in this chapter to fill in the missing data. Find the regression of FEV1 on height and weight using the imputed values. Compare the results using the imputed data with those from the original data set.