Finding the Fourth Proportional to 10,420.70, 14,380.86 and 5,705.28

Step by Step Solution

1. Step 1: Write the proportion equation
   10,420.70 : 14,380.86 = 5,705.28 : x
2. Step 2: Convert to fraction form
   10,420.70/14,380.86 = 5,705.28/x
3. Step 3: Cross multiply
   10,420.70x = 14,380.86 × 5,705.28
4. Step 4: Simplify right side
   10,420.70x = 82,046,832.94
5. Step 5: Solve for x
   x = 82,046,832.94/10,420.70
6. Step 6: Final answer
   x = 7,873.45