Finding the Fourth Proportional to 1,087.50, 1,630.71 and 438.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,087.50 : 1,630.71 = 438.06 : x
2. Step 2: Convert to fraction form
   1,087.50/1,630.71 = 438.06/x
3. Step 3: Cross multiply
   1,087.50x = 1,630.71 × 438.06
4. Step 4: Simplify right side
   1,087.50x = 714,348.82
5. Step 5: Solve for x
   x = 714,348.82/1,087.50
6. Step 6: Final answer
   x = 656.87