Finding the Fourth Proportional to 78,931.72, 108,938.10 and 50,667.40

Step by Step Solution

1. Step 1: Write the proportion equation
   78,931.72 : 108,938.10 = 50,667.40 : x
2. Step 2: Convert to fraction form
   78,931.72/108,938.10 = 50,667.40/x
3. Step 3: Cross multiply
   78,931.72x = 108,938.10 × 50,667.40
4. Step 4: Simplify right side
   78,931.72x = 5,519,610,287.94
5. Step 5: Solve for x
   x = 5,519,610,287.94/78,931.72
6. Step 6: Final answer
   x = 69,928.92