Finding the Fourth Proportional to 1,119.96, 1,680.71 and 389.53

Step by Step Solution

1. Step 1: Write the proportion equation
   1,119.96 : 1,680.71 = 389.53 : x
2. Step 2: Convert to fraction form
   1,119.96/1,680.71 = 389.53/x
3. Step 3: Cross multiply
   1,119.96x = 1,680.71 × 389.53
4. Step 4: Simplify right side
   1,119.96x = 654,685.02
5. Step 5: Solve for x
   x = 654,685.02/1,119.96
6. Step 6: Final answer
   x = 584.56