Finding the Fourth Proportional to 100,648.48, 138,907.98 and 64,942.36

Step by Step Solution

1. Step 1: Write the proportion equation
   100,648.48 : 138,907.98 = 64,942.36 : x
2. Step 2: Convert to fraction form
   100,648.48/138,907.98 = 64,942.36/x
3. Step 3: Cross multiply
   100,648.48x = 138,907.98 × 64,942.36
4. Step 4: Simplify right side
   100,648.48x = 9,021,012,044.03
5. Step 5: Solve for x
   x = 9,021,012,044.03/100,648.48
6. Step 6: Final answer
   x = 89,628.89