Finding the Fourth Proportional to 1,345.79, 1,857.05 and 756.21

Step by Step Solution

1. Step 1: Write the proportion equation
   1,345.79 : 1,857.05 = 756.21 : x
2. Step 2: Convert to fraction form
   1,345.79/1,857.05 = 756.21/x
3. Step 3: Cross multiply
   1,345.79x = 1,857.05 × 756.21
4. Step 4: Simplify right side
   1,345.79x = 1,404,322.70
5. Step 5: Solve for x
   x = 1,404,322.70/1,345.79
6. Step 6: Final answer
   x = 1,043.49