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Data Acquisition and PreparationmediumMultiple SelectObjective-mapped

DA0-002 Data Acquisition and Preparation Practice Question

An analyst needs to identify outliers in a numeric column 'transaction_amount' using the interquartile range (IQR) method. Which TWO steps are part of this process? (Select TWO).

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

Subtract 1.5 times the IQR from Q1 and add 1.5 times the IQR to Q3 to define bounds

The IQR method involves calculating Q1 and Q3 to find IQR, then defining lower and upper bounds as Q1 - 1.5*IQR and Q3 + 1.5*IQR. Computing mean and standard deviation is for Z-score method; calculating median alone is insufficient.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

  • Subtract 1.5 times the IQR from Q1 and add 1.5 times the IQR to Q3 to define bounds

    Why this is correct

    These bounds are used to flag outliers.

  • Calculate the median of the column

    Why it's wrong here

    Median is not directly used in the IQR method for outlier detection.

  • Calculate the first quartile (Q1) and third quartile (Q3)

    Why this is correct

    Q1 and Q3 are needed to compute IQR.

  • Sort the data and remove the top and bottom 5%

    Why it's wrong here

    This is a different trimming approach, not IQR.

  • Compute the mean and standard deviation of the column

    Why it's wrong here

    These are used in Z-score method, not IQR.

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