Finding the Fourth Proportional to 10,641.78, 15,970.37 and 7,138.53

Step by Step Solution

1. Step 1: Write the proportion equation
   10,641.78 : 15,970.37 = 7,138.53 : x
2. Step 2: Convert to fraction form
   10,641.78/15,970.37 = 7,138.53/x
3. Step 3: Cross multiply
   10,641.78x = 15,970.37 × 7,138.53
4. Step 4: Simplify right side
   10,641.78x = 114,004,929.66
5. Step 5: Solve for x
   x = 114,004,929.66/10,641.78
6. Step 6: Final answer
   x = 10,712.96