The known number 40 corresponds to 3.0 The number 42.1 corresponds to X The number 45 corresponds to 1.5 How much is x by interpolation, My friend on the first floor, the formula you gave is wrong, 2.25 - (42.5-42.1) × 5 = 2.05.

The known number 40 corresponds to 3.0 The number 42.1 corresponds to X The number 45 corresponds to 1.5 How much is x by interpolation, My friend on the first floor, the formula you gave is wrong, 2.25 - (42.5-42.1) × 5 = 2.05.

The number 40 corresponds to 3.0
The number 45 corresponds to 1.5
===>42.5 corresponds to 2.25
The number 40 corresponds to 3.0
42.5 corresponds to 2.25
===>42.1 corresponds to 2.25 - (42.5-42.1) * 5 = 2.05