Finding the Fourth Proportional to 2,978.72, 4,467.60 and 1,129.40

Step by Step Solution

1. Step 1: Write the proportion equation
   2,978.72 : 4,467.60 = 1,129.40 : x
2. Step 2: Convert to fraction form
   2,978.72/4,467.60 = 1,129.40/x
3. Step 3: Cross multiply
   2,978.72x = 4,467.60 × 1,129.40
4. Step 4: Simplify right side
   2,978.72x = 5,045,707.44
5. Step 5: Solve for x
   x = 5,045,707.44/2,978.72
6. Step 6: Final answer
   x = 1,693.92