Table schema:
CREATE TABLE table_name_30 (_inches VARCHAR, skin_depth INTEGER, resistivity__10_−6_ohm_inches_ VARCHAR, relative_permeability VARCHAR)

Question: What is the sum of skin depth with a resistivity of 1.12 and a relative permeability larger than 1?
SQL: SELECT SUM(skin_depth), _inches FROM table_name_30 WHERE resistivity__10_−6_ohm_inches_ = 1.12 AND relative_permeability > 1