Finding the Fourth Proportional to 1,398.58, 1,934.22 and 1,228.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.58 : 1,934.22 = 1,228.48 : x
2. Step 2: Convert to fraction form
   1,398.58/1,934.22 = 1,228.48/x
3. Step 3: Cross multiply
   1,398.58x = 1,934.22 × 1,228.48
4. Step 4: Simplify right side
   1,398.58x = 2,376,150.59
5. Step 5: Solve for x
   x = 2,376,150.59/1,398.58
6. Step 6: Final answer
   x = 1,698.97