4 You are the project manager for a data analysis firm. You are supervising the data integrity process for a large survey on personal hygiene issues. The data were collected via a postal survey and 1,823 questionnaires have been returned. The response rate was excellent, partially due to an enticing prize draw that accompanied the survey. However, you are suspicious about the quality of many responses and 290 questionnaires have missing responses.

The data analyst preparing the data has not seen such a level of missing data and does not know how to cope with this survey. Explain to the data analyst how the missing responses and checks on the quality of data to be analysed should be performed.