Finding the Fourth Proportional to 2,109.18, 3,165.68 and 1,069.90

Step by Step Solution

1. Step 1: Write the proportion equation
   2,109.18 : 3,165.68 = 1,069.90 : x
2. Step 2: Convert to fraction form
   2,109.18/3,165.68 = 1,069.90/x
3. Step 3: Cross multiply
   2,109.18x = 3,165.68 × 1,069.90
4. Step 4: Simplify right side
   2,109.18x = 3,386,961.03
5. Step 5: Solve for x
   x = 3,386,961.03/2,109.18
6. Step 6: Final answer
   x = 1,605.82