Calculation formula of qualified rate = number of qualified products ÷ total number of products × 100%.
Since it is a few percent, of course, it is multiplied by 100%, which can describe the quality of the product more intuitively.
If you want to increase it by a few percent, you need to multiply it by 100%. For example, if you find an increase of 0.5, you have to multiply it by 100% to become 50%, which means an increase of 50%.