Finding the Fourth Proportional to 1,187.52, 1,638.84 and 663.54

Step by Step Solution

1. Step 1: Write the proportion equation
   1,187.52 : 1,638.84 = 663.54 : x
2. Step 2: Convert to fraction form
   1,187.52/1,638.84 = 663.54/x
3. Step 3: Cross multiply
   1,187.52x = 1,638.84 × 663.54
4. Step 4: Simplify right side
   1,187.52x = 1,087,435.89
5. Step 5: Solve for x
   x = 1,087,435.89/1,187.52
6. Step 6: Final answer
   x = 915.72