Finding the Fourth Proportional to 105,290.09, 145,300.34 and 57,543.43

Step by Step Solution

1. Step 1: Write the proportion equation
   105,290.09 : 145,300.34 = 57,543.43 : x
2. Step 2: Convert to fraction form
   105,290.09/145,300.34 = 57,543.43/x
3. Step 3: Cross multiply
   105,290.09x = 145,300.34 × 57,543.43
4. Step 4: Simplify right side
   105,290.09x = 8,361,079,724.37
5. Step 5: Solve for x
   x = 8,361,079,724.37/105,290.09
6. Step 6: Final answer
   x = 79,409.94