Finding the Fourth Proportional to 1,430.78, 2,146.04 and 456.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,430.78 : 2,146.04 = 456.72 : x
2. Step 2: Convert to fraction form
   1,430.78/2,146.04 = 456.72/x
3. Step 3: Cross multiply
   1,430.78x = 2,146.04 × 456.72
4. Step 4: Simplify right side
   1,430.78x = 980,139.39
5. Step 5: Solve for x
   x = 980,139.39/1,430.78
6. Step 6: Final answer
   x = 685.04