Finding the Fourth Proportional to 1,298.76, 1,792.30 and 709.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,298.76 : 1,792.30 = 709.31 : x
2. Step 2: Convert to fraction form
   1,298.76/1,792.30 = 709.31/x
3. Step 3: Cross multiply
   1,298.76x = 1,792.30 × 709.31
4. Step 4: Simplify right side
   1,298.76x = 1,271,296.31
5. Step 5: Solve for x
   x = 1,271,296.31/1,298.76
6. Step 6: Final answer
   x = 978.85