Finding the Fourth Proportional to 105,268.72, 145,270.74 and 56,870.65

Step by Step Solution

1. Step 1: Write the proportion equation
   105,268.72 : 145,270.74 = 56,870.65 : x
2. Step 2: Convert to fraction form
   105,268.72/145,270.74 = 56,870.65/x
3. Step 3: Cross multiply
   105,268.72x = 145,270.74 × 56,870.65
4. Step 4: Simplify right side
   105,268.72x = 8,261,641,409.78
5. Step 5: Solve for x
   x = 8,261,641,409.78/105,268.72
6. Step 6: Final answer
   x = 78,481.45