Explain the Height of Instrument (H.I.) method for auto level survey, including its formulas and key principles.

Here is the solution for the auto level survey table using the Height of Instrument (H.I.) method:

Step 1: Understand the formulas for H.I. method
The core formulas for the H.I. method are:

• $\text{HI} = \text{RL}_{\text{known}} + \text{BS}$ (Height of Instrument = Reduced Level of a known point + Backsight reading)
• $\text{RL} = \text{HI} - \text{IS}$ (Reduced Level = Height of Instrument - Intermediate Sight reading)
• $\text{RL} = \text{HI} - \text{FS}$ (Reduced Level = Height of Instrument - Foresight reading)

The HI remains constant for all readings taken