Finding the Fourth Proportional to 105,428.21, 145,514.27 and 72,768.47

Step by Step Solution

1. Step 1: Write the proportion equation
   105,428.21 : 145,514.27 = 72,768.47 : x
2. Step 2: Convert to fraction form
   105,428.21/145,514.27 = 72,768.47/x
3. Step 3: Cross multiply
   105,428.21x = 145,514.27 × 72,768.47
4. Step 4: Simplify right side
   105,428.21x = 10,588,849,699.65
5. Step 5: Solve for x
   x = 10,588,849,699.65/105,428.21
6. Step 6: Final answer
   x = 100,436.59