B4. The Polit2SetC dataset includes the variable cesd, which is a total CES-D score for cases with nonmissing values, plus cases for whom missing values were imputed using case mean substitution. (The imputation was done only for cases that had no more than five missing values.) Looking at the output for Exercise B2, how many cases should have a CES-D score? Confirm that your answer corresponds to what is in the dataset by running descriptive statistics on cesd. (Note that CES-D scores were computed by adding together all item values with appropriate item reversals, and then subtracting 20. This is because the original CES-D scale uses codes of 0, 1, 2, and 3, rather than 1, 2, 3, and 4.

It is desirable to have scores on the same scale as the original because cutoff scores are used to establish whether a person is at risk or at high risk of clinical depression.)