Finding the Fourth Proportional to 1,109.78, 1,664.69 and 525.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,109.78 : 1,664.69 = 525.05 : x
2. Step 2: Convert to fraction form
   1,109.78/1,664.69 = 525.05/x
3. Step 3: Cross multiply
   1,109.78x = 1,664.69 × 525.05
4. Step 4: Simplify right side
   1,109.78x = 874,048.17
5. Step 5: Solve for x
   x = 874,048.17/1,109.78
6. Step 6: Final answer
   x = 787.59