Finding the Fourth Proportional to 1,384.56, 1,919.79 and 1,338.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,384.56 : 1,919.79 = 1,338.30 : x
2. Step 2: Convert to fraction form
   1,384.56/1,919.79 = 1,338.30/x
3. Step 3: Cross multiply
   1,384.56x = 1,919.79 × 1,338.30
4. Step 4: Simplify right side
   1,384.56x = 2,569,254.96
5. Step 5: Solve for x
   x = 2,569,254.96/1,384.56
6. Step 6: Final answer
   x = 1,855.65