Finding the Fourth Proportional to 1,345.76, 1,857.28 and 756.40

Step by Step Solution

1. Step 1: Write the proportion equation
   1,345.76 : 1,857.28 = 756.40 : x
2. Step 2: Convert to fraction form
   1,345.76/1,857.28 = 756.40/x
3. Step 3: Cross multiply
   1,345.76x = 1,857.28 × 756.40
4. Step 4: Simplify right side
   1,345.76x = 1,404,846.59
5. Step 5: Solve for x
   x = 1,404,846.59/1,345.76
6. Step 6: Final answer
   x = 1,043.91