Finding the Fourth Proportional to 1,123.61, 1,685.00 and 880.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,123.61 : 1,685.00 = 880.61 : x
2. Step 2: Convert to fraction form
   1,123.61/1,685.00 = 880.61/x
3. Step 3: Cross multiply
   1,123.61x = 1,685.00 × 880.61
4. Step 4: Simplify right side
   1,123.61x = 1,483,821.63
5. Step 5: Solve for x
   x = 1,483,821.63/1,123.61
6. Step 6: Final answer
   x = 1,320.59