Finding the Fourth Proportional to 1,111.61, 1,666.30 and 525.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.61 : 1,666.30 = 525.56 : x
2. Step 2: Convert to fraction form
   1,111.61/1,666.30 = 525.56/x
3. Step 3: Cross multiply
   1,111.61x = 1,666.30 × 525.56
4. Step 4: Simplify right side
   1,111.61x = 875,743.48
5. Step 5: Solve for x
   x = 875,743.48/1,111.61
6. Step 6: Final answer
   x = 787.82