Finding the Fourth Proportional to 1,258.43, 1,736.61 and 691.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,258.43 : 1,736.61 = 691.28 : x
2. Step 2: Convert to fraction form
   1,258.43/1,736.61 = 691.28/x
3. Step 3: Cross multiply
   1,258.43x = 1,736.61 × 691.28
4. Step 4: Simplify right side
   1,258.43x = 1,200,483.76
5. Step 5: Solve for x
   x = 1,200,483.76/1,258.43
6. Step 6: Final answer
   x = 953.95