Finding the Fourth Proportional to 1,258.20, 1,736.42 and 698.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,258.20 : 1,736.42 = 698.72 : x
2. Step 2: Convert to fraction form
   1,258.20/1,736.42 = 698.72/x
3. Step 3: Cross multiply
   1,258.20x = 1,736.42 × 698.72
4. Step 4: Simplify right side
   1,258.20x = 1,213,267.89
5. Step 5: Solve for x
   x = 1,213,267.89/1,258.20
6. Step 6: Final answer
   x = 964.29