Finding the Fourth Proportional to 13,888.78, 19,166.43 and 7,920.32

Step by Step Solution

1. Step 1: Write the proportion equation
   13,888.78 : 19,166.43 = 7,920.32 : x
2. Step 2: Convert to fraction form
   13,888.78/19,166.43 = 7,920.32/x
3. Step 3: Cross multiply
   13,888.78x = 19,166.43 × 7,920.32
4. Step 4: Simplify right side
   13,888.78x = 151,804,192.73
5. Step 5: Solve for x
   x = 151,804,192.73/13,888.78
6. Step 6: Final answer
   x = 10,929.99