Finding the Fourth Proportional to 105.42, 145.10 and 100.82

Step by Step Solution

1. Step 1: Write the proportion equation
   105.42 : 145.10 = 100.82 : x
2. Step 2: Convert to fraction form
   105.42/145.10 = 100.82/x
3. Step 3: Cross multiply
   105.42x = 145.10 × 100.82
4. Step 4: Simplify right side
   105.42x = 14,627.75
5. Step 5: Solve for x
   x = 14,627.75/105.42
6. Step 6: Final answer
   x = 138.76