Question 1

a) What will the following Python statement do?

df.drop(df.std()[df.std() == 0].index, axis = 1) 

Drop both the categorical and numericalvariables with zero variance

Drop the variables with zero weightedaverage

Drop the numerical variables with zerovariance (or standard deviation)

None of the options

B) Which of the following statements is correct?

If a dataset has a variable in which all therecords are the same, you can drop that variable

If a dataset has a variable in which the majorityof the records are missing (e.g., 90%), you can drop thatvariable

If a dataset has a categorical variable, you needto create new variable(s) to represent that variable withnumbers

All of the options

C) If a dataset has a categorical variable namedoccupation with m levels, how many new dummy variables the codebelow will create?

pd.get_dummies(df['occupation'], drop_first = False) 

m

m+1

m-1

None of the options