Finding the Fourth Proportional to 1,398.15, 1,929.18 and 900.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.15 : 1,929.18 = 900.69 : x
2. Step 2: Convert to fraction form
   1,398.15/1,929.18 = 900.69/x
3. Step 3: Cross multiply
   1,398.15x = 1,929.18 × 900.69
4. Step 4: Simplify right side
   1,398.15x = 1,737,593.13
5. Step 5: Solve for x
   x = 1,737,593.13/1,398.15
6. Step 6: Final answer
   x = 1,242.78