Finding the Fourth Proportional to 1,151.29, 1,725.58 and 780.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,151.29 : 1,725.58 = 780.31 : x
2. Step 2: Convert to fraction form
   1,151.29/1,725.58 = 780.31/x
3. Step 3: Cross multiply
   1,151.29x = 1,725.58 × 780.31
4. Step 4: Simplify right side
   1,151.29x = 1,346,487.33
5. Step 5: Solve for x
   x = 1,346,487.33/1,151.29
6. Step 6: Final answer
   x = 1,169.55