哦。自己找到了：
According to the factor reversal test if the factors i.e. Price and quantity in a price or quantity index formula be interchanged so that a quantity or price index number formula is obtained, then the product of these formulae should be the value index number.

Pon X  Qon= summation pnqn/ summation poqo.

These test are used to check that which method is best to calculate index number. These tests are used to check the accuracy of the index number obtained from different resources. They help to compare the values of index numbers.

According to the factor reversal test if the factors i.e. Price and quantity in a price or quantity index formula be interchanged so that a quantity or price index number formula is obtained, then the product of these formulae should be the value index number.

Pon X  Qon= summation pnqn/ summation poqo.

These test are used to check that which method is best to calculate index number. These tests are used to check the accuracy of the index number obtained from different resources. They help to compare the values of index numbers