Finding the Fourth Proportional to 105,587.42, 145,655.40 and 65,288.30

Step by Step Solution

1. Step 1: Write the proportion equation
   105,587.42 : 145,655.40 = 65,288.30 : x
2. Step 2: Convert to fraction form
   105,587.42/145,655.40 = 65,288.30/x
3. Step 3: Cross multiply
   105,587.42x = 145,655.40 × 65,288.30
4. Step 4: Simplify right side
   105,587.42x = 9,509,593,451.82
5. Step 5: Solve for x
   x = 9,509,593,451.82/105,587.42
6. Step 6: Final answer
   x = 90,063.70