Finding the Fourth Proportional to 2,986.72, 4,478.58 and 1,038.40

Step by Step Solution

1. Step 1: Write the proportion equation
   2,986.72 : 4,478.58 = 1,038.40 : x
2. Step 2: Convert to fraction form
   2,986.72/4,478.58 = 1,038.40/x
3. Step 3: Cross multiply
   2,986.72x = 4,478.58 × 1,038.40
4. Step 4: Simplify right side
   2,986.72x = 4,650,557.47
5. Step 5: Solve for x
   x = 4,650,557.47/2,986.72
6. Step 6: Final answer
   x = 1,557.08