Finding the Fourth Proportional to 1,408.86, 2,111.67 and 921.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,408.86 : 2,111.67 = 921.06 : x
2. Step 2: Convert to fraction form
   1,408.86/2,111.67 = 921.06/x
3. Step 3: Cross multiply
   1,408.86x = 2,111.67 × 921.06
4. Step 4: Simplify right side
   1,408.86x = 1,944,974.77
5. Step 5: Solve for x
   x = 1,944,974.77/1,408.86
6. Step 6: Final answer
   x = 1,380.53