Finding the Fourth Proportional to 1,380.84, 1,905.83 and 783.35

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.84 : 1,905.83 = 783.35 : x
2. Step 2: Convert to fraction form
   1,380.84/1,905.83 = 783.35/x
3. Step 3: Cross multiply
   1,380.84x = 1,905.83 × 783.35
4. Step 4: Simplify right side
   1,380.84x = 1,492,922.40
5. Step 5: Solve for x
   x = 1,492,922.40/1,380.84
6. Step 6: Final answer
   x = 1,081.17