Finding the Fourth Proportional to 1,087.52, 1,500.71 and 645.26

Step by Step Solution

1. Step 1: Write the proportion equation
   1,087.52 : 1,500.71 = 645.26 : x
2. Step 2: Convert to fraction form
   1,087.52/1,500.71 = 645.26/x
3. Step 3: Cross multiply
   1,087.52x = 1,500.71 × 645.26
4. Step 4: Simplify right side
   1,087.52x = 968,337.40
5. Step 5: Solve for x
   x = 968,337.40/1,087.52
6. Step 6: Final answer
   x = 890.41