Part II: Observational study Sharkville is a small beach town where tourists go to enjoy ice cream and surfing. During the pandemic, the Sharkville Municipal Hospital (SMH) surveyed all of its employees and its patients. In this survey, the hospital collected data on 1) whether individuals had contracted COVID-19, 2) whether they were vaccinated against COVID-19, and 3) other demographic characteristics. The dataset for the resulting survey is SMH_f2023.dta. Open this dataset in STATA and answer the following questions. 1. Data Cleaning Datasets may sometimes contain errors. Data cleaning and checking is an important step in data analysis. a. (1pt) The variable id is a unique identifier for each survey entry. Check that there are no duplicate entries and if there are any, remove them from the dataset. What did you find? (Hint: Try 'help duplicates' in your STATA command box). b. (1pt) Summarize all of the variables in the dataset. See if you spot anything that should not be there. Remove entries/data which may have been entered by mistake.