Finding the Fourth Proportional to 78,145.38, 117,223.47 and 31,398.30

Step by Step Solution

1. Step 1: Write the proportion equation
   78,145.38 : 117,223.47 = 31,398.30 : x
2. Step 2: Convert to fraction form
   78,145.38/117,223.47 = 31,398.30/x
3. Step 3: Cross multiply
   78,145.38x = 117,223.47 × 31,398.30
4. Step 4: Simplify right side
   78,145.38x = 3,680,617,678.10
5. Step 5: Solve for x
   x = 3,680,617,678.10/78,145.38
6. Step 6: Final answer
   x = 47,099.62