Finding the Fourth Proportional to 1,298.38, 1,947.16 and 420.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,298.38 : 1,947.16 = 420.69 : x
2. Step 2: Convert to fraction form
   1,298.38/1,947.16 = 420.69/x
3. Step 3: Cross multiply
   1,298.38x = 1,947.16 × 420.69
4. Step 4: Simplify right side
   1,298.38x = 819,156.20
5. Step 5: Solve for x
   x = 819,156.20/1,298.38
6. Step 6: Final answer
   x = 630.91