Finding the Fourth Proportional to 1,398.56, 1,930.10 and 926.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.56 : 1,930.10 = 926.15 : x
2. Step 2: Convert to fraction form
   1,398.56/1,930.10 = 926.15/x
3. Step 3: Cross multiply
   1,398.56x = 1,930.10 × 926.15
4. Step 4: Simplify right side
   1,398.56x = 1,787,547.83
5. Step 5: Solve for x
   x = 1,787,547.83/1,398.56
6. Step 6: Final answer
   x = 1,278.14