Finding the Fourth Proportional to 105,290.42, 145,300.43 and 57,543.76

Step by Step Solution

1. Step 1: Write the proportion equation
   105,290.42 : 145,300.43 = 57,543.76 : x
2. Step 2: Convert to fraction form
   105,290.42/145,300.43 = 57,543.76/x
3. Step 3: Cross multiply
   105,290.42x = 145,300.43 × 57,543.76
4. Step 4: Simplify right side
   105,290.42x = 8,361,133,071.82
5. Step 5: Solve for x
   x = 8,361,133,071.82/105,290.42
6. Step 6: Final answer
   x = 79,410.20