Finding the Fourth Proportional to 100,648.47, 138,907.98 and 64,942.35

Step by Step Solution

1. Step 1: Write the proportion equation
   100,648.47 : 138,907.98 = 64,942.35 : x
2. Step 2: Convert to fraction form
   100,648.47/138,907.98 = 64,942.35/x
3. Step 3: Cross multiply
   100,648.47x = 138,907.98 × 64,942.35
4. Step 4: Simplify right side
   100,648.47x = 9,021,010,654.95
5. Step 5: Solve for x
   x = 9,021,010,654.95/100,648.47
6. Step 6: Final answer
   x = 89,628.89