Among the female customers with an level of education of 3 and below, list their income.
female customers with level of education of 3 and below refer to SEX = 'Female' where EDUCATIONNUM ≤ 3; income refers to INCOME_K;
SELECT INCOME_K FROM Demog WHERE GEOID IN ( SELECT GEOID FROM Customers WHERE EDUCATIONNUM < 3 AND SEX = 'Female' )