Finding the Fourth Proportional to 3,139.30, 4,707.78 and 947.32

Step by Step Solution

1. Step 1: Write the proportion equation
   3,139.30 : 4,707.78 = 947.32 : x
2. Step 2: Convert to fraction form
   3,139.30/4,707.78 = 947.32/x
3. Step 3: Cross multiply
   3,139.30x = 4,707.78 × 947.32
4. Step 4: Simplify right side
   3,139.30x = 4,459,774.15
5. Step 5: Solve for x
   x = 4,459,774.15/3,139.30
6. Step 6: Final answer
   x = 1,420.63