Finding the Fourth Proportional to 105.47, 145.55 and 61.82

Step by Step Solution

1. Step 1: Write the proportion equation
   105.47 : 145.55 = 61.82 : x
2. Step 2: Convert to fraction form
   105.47/145.55 = 61.82/x
3. Step 3: Cross multiply
   105.47x = 145.55 × 61.82
4. Step 4: Simplify right side
   105.47x = 8,997.90
5. Step 5: Solve for x
   x = 8,997.90/105.47
6. Step 6: Final answer
   x = 85.31