Finding the Fourth Proportional to 1,298.71, 1,792.20 and 709.24

Step by Step Solution

1. Step 1: Write the proportion equation
   1,298.71 : 1,792.20 = 709.24 : x
2. Step 2: Convert to fraction form
   1,298.71/1,792.20 = 709.24/x
3. Step 3: Cross multiply
   1,298.71x = 1,792.20 × 709.24
4. Step 4: Simplify right side
   1,298.71x = 1,271,099.93
5. Step 5: Solve for x
   x = 1,271,099.93/1,298.71
6. Step 6: Final answer
   x = 978.74