The question I should have asked was which restaurant you think has the highest Z score, as remarked by a third fellow. Chinese and Japanese restaurants each have their own Normal distribution in one’s mind, as illustrated below. The average restaurant has a Z score of zero and, as it turns out, the Japanese in question has one around 0,8 while the Chinese one around 0,5. The Japanese is the preferred one, while they are both above average. Now it’s clear!