CREATE TABLE phone (chip_model VARCHAR2, Company_name VARCHAR2)
CREATE TABLE chip_model (ROM_MiB NUMBER, Model_name VARCHAR2)

What is the average ROM size of phones produced by the company named 'Nokia Corporation'?
SELECT AVG(T1.ROM_MiB) FROM chip_model AS T1 JOIN phone AS T2 ON T1.Model_name = T2.chip_model WHERE T2.Company_name = "Nokia Corporation"
SELECT AVG("T1"."ROM_MiB") FROM "chip_model" "T1" JOIN "phone" "T2" ON "Nokia Corporation" = "T2"."Company_name" AND "T1"."Model_name" = "T2"."chip_model"