Finding the Fourth Proportional to 2,947.25, 4,420.78 and 999.47

Step by Step Solution

1. Step 1: Write the proportion equation
   2,947.25 : 4,420.78 = 999.47 : x
2. Step 2: Convert to fraction form
   2,947.25/4,420.78 = 999.47/x
3. Step 3: Cross multiply
   2,947.25x = 4,420.78 × 999.47
4. Step 4: Simplify right side
   2,947.25x = 4,418,445.54
5. Step 5: Solve for x
   x = 4,418,445.54/2,947.25
6. Step 6: Final answer
   x = 1,499.17