Finding the Fourth Proportional to 105.45, 145.42 and 70.42

Step by Step Solution

1. Step 1: Write the proportion equation
   105.45 : 145.42 = 70.42 : x
2. Step 2: Convert to fraction form
   105.45/145.42 = 70.42/x
3. Step 3: Cross multiply
   105.45x = 145.42 × 70.42
4. Step 4: Simplify right side
   105.45x = 10,240.48
5. Step 5: Solve for x
   x = 10,240.48/105.45
6. Step 6: Final answer
   x = 97.11