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Handling 30% Missing Critical Data
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Handling 30% Missing Critical Data

MediumSQL · PostgreSQL

Problem

How would you handle a dataset where 30% of the entries are missing critical information at American Credit Acceptance?

For this exercise, evaluate completeness for each loan application source. Treat NULL or blank employment status, and NULL values in income, requested amount, or credit score as missing critical information.

Output

  1. One row per application source, including applications with no matching source.
  2. Columns: source_name, total_entries, missing_entries, and missing_percentage.
  3. Sort by missing percentage descending, then source name ascending.

Schema

loan_applications
ColumnTypeDescription
application_idPKINTUnique loan application identifier
source_idINTIdentifier of the application submission source
annual_incomeDECIMAL(12,2)Applicant annual income
employment_statusVARCHAR(40)Applicant employment status
requested_amountDECIMAL(12,2)Requested loan amount
credit_scoreINTApplicant credit score
application_sources
ColumnTypeDescription
source_idPKINTUnique application source identifier
source_nameVARCHAR(60)Name of the application submission source
Tablesloan_applicationsapplication_sources
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