Finding the Fourth Proportional to 105.98, 145.48 and 100.58

Step by Step Solution

1. Step 1: Write the proportion equation
   105.98 : 145.48 = 100.58 : x
2. Step 2: Convert to fraction form
   105.98/145.48 = 100.58/x
3. Step 3: Cross multiply
   105.98x = 145.48 × 100.58
4. Step 4: Simplify right side
   105.98x = 14,632.38
5. Step 5: Solve for x
   x = 14,632.38/105.98
6. Step 6: Final answer
   x = 138.07