Finding the Fourth Proportional to 1,153.25, 1,591.50 and 687.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,153.25 : 1,591.50 = 687.50 : x
2. Step 2: Convert to fraction form
   1,153.25/1,591.50 = 687.50/x
3. Step 3: Cross multiply
   1,153.25x = 1,591.50 × 687.50
4. Step 4: Simplify right side
   1,153.25x = 1,094,156.25
5. Step 5: Solve for x
   x = 1,094,156.25/1,153.25
6. Step 6: Final answer
   x = 948.76