SELECT avg(RAM_MiB) FROM chip_model WHERE model_name NOT IN (SELECT chip_model FROM phone)
Find the average ram mib size of the chip models that are never used by any phone.
SELECT avg ( RAM_MiB ) FROM chip_model WHERE model_name NOT IN ( SELECT chip_model FROM phone )
select avg ( ram_mib ) from chip_model where model_name not in ( select chip_model from phone )
Find the average ram mib size of the chip models that are never used by any phone .