Finding the Fourth Proportional to 105,421.74, 145,485.45 and 57,673.98

Step by Step Solution

1. Step 1: Write the proportion equation
   105,421.74 : 145,485.45 = 57,673.98 : x
2. Step 2: Convert to fraction form
   105,421.74/145,485.45 = 57,673.98/x
3. Step 3: Cross multiply
   105,421.74x = 145,485.45 × 57,673.98
4. Step 4: Simplify right side
   105,421.74x = 8,390,724,933.59
5. Step 5: Solve for x
   x = 8,390,724,933.59/105,421.74
6. Step 6: Final answer
   x = 79,591.98