Finding the Fourth Proportional to 105.42, 145.42 and 74.32

Step by Step Solution

1. Step 1: Write the proportion equation
   105.42 : 145.42 = 74.32 : x
2. Step 2: Convert to fraction form
   105.42/145.42 = 74.32/x
3. Step 3: Cross multiply
   105.42x = 145.42 × 74.32
4. Step 4: Simplify right side
   105.42x = 10,807.61
5. Step 5: Solve for x
   x = 10,807.61/105.42
6. Step 6: Final answer
   x = 102.52