Finding the Fourth Proportional to 1,550.80, 2,139.54 and 1,215.94

Step by Step Solution

1. Step 1: Write the proportion equation
   1,550.80 : 2,139.54 = 1,215.94 : x
2. Step 2: Convert to fraction form
   1,550.80/2,139.54 = 1,215.94/x
3. Step 3: Cross multiply
   1,550.80x = 2,139.54 × 1,215.94
4. Step 4: Simplify right side
   1,550.80x = 2,601,552.27
5. Step 5: Solve for x
   x = 2,601,552.27/1,550.80
6. Step 6: Final answer
   x = 1,677.55