Finding the Fourth Proportional to 2,019.84, 2,787.36 and 1,223.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,019.84 : 2,787.36 = 1,223.20 : x
2. Step 2: Convert to fraction form
   2,019.84/2,787.36 = 1,223.20/x
3. Step 3: Cross multiply
   2,019.84x = 2,787.36 × 1,223.20
4. Step 4: Simplify right side
   2,019.84x = 3,409,498.75
5. Step 5: Solve for x
   x = 3,409,498.75/2,019.84
6. Step 6: Final answer
   x = 1,688.00