If you're trying to make a 6" screen and a 27" screen at the same dpi and aspect ratio, and the 6" have unacceptable defects 1% of the time, the 27" screens will be defective at 4.5^2 times that rate, or about 20%.
If you're trying to make a 6" screen and a 27" screen at the same dpi and aspect ratio, and the 6" have unacceptable defects 1% of the time, the 27" screens will be defective at 4.5^2 times that rate, or about 20%.