Finding the Fourth Proportional to 2,086.21, 3,128.55 and 624.87

Step by Step Solution

1. Step 1: Write the proportion equation
   2,086.21 : 3,128.55 = 624.87 : x
2. Step 2: Convert to fraction form
   2,086.21/3,128.55 = 624.87/x
3. Step 3: Cross multiply
   2,086.21x = 3,128.55 × 624.87
4. Step 4: Simplify right side
   2,086.21x = 1,954,937.04
5. Step 5: Solve for x
   x = 1,954,937.04/2,086.21
6. Step 6: Final answer
   x = 937.08