Finding the Fourth Proportional to 1,151.70, 1,588.59 and 685.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,151.70 : 1,588.59 = 685.50 : x
2. Step 2: Convert to fraction form
   1,151.70/1,588.59 = 685.50/x
3. Step 3: Cross multiply
   1,151.70x = 1,588.59 × 685.50
4. Step 4: Simplify right side
   1,151.70x = 1,088,978.45
5. Step 5: Solve for x
   x = 1,088,978.45/1,151.70
6. Step 6: Final answer
   x = 945.54