Finding the Fourth Proportional to 1,138.68, 1,569.72 and 696.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,138.68 : 1,569.72 = 696.30 : x
2. Step 2: Convert to fraction form
   1,138.68/1,569.72 = 696.30/x
3. Step 3: Cross multiply
   1,138.68x = 1,569.72 × 696.30
4. Step 4: Simplify right side
   1,138.68x = 1,092,996.04
5. Step 5: Solve for x
   x = 1,092,996.04/1,138.68
6. Step 6: Final answer
   x = 959.88