Finding the Fourth Proportional to 1,215.10, 1,706 and 1,215.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,215.10 : 1,706 = 1,215.10 : x
2. Step 2: Convert to fraction form
   1,215.10/1,706 = 1,215.10/x
3. Step 3: Cross multiply
   1,215.10x = 1,706 × 1,215.10
4. Step 4: Simplify right side
   1,215.10x = 2,072,960.60
5. Step 5: Solve for x
   x = 2,072,960.60/1,215.10
6. Step 6: Final answer
   x = 1,706