Finding the Fourth Proportional to 10,115.78, 13,964.72 and 7,842

Step by Step Solution

1. Step 1: Write the proportion equation
   10,115.78 : 13,964.72 = 7,842 : x
2. Step 2: Convert to fraction form
   10,115.78/13,964.72 = 7,842/x
3. Step 3: Cross multiply
   10,115.78x = 13,964.72 × 7,842
4. Step 4: Simplify right side
   10,115.78x = 109,511,334.24
5. Step 5: Solve for x
   x = 109,511,334.24/10,115.78
6. Step 6: Final answer
   x = 10,825.79