Finding the Fourth Proportional to 105.42, 145.38 and 74.34

Step by Step Solution

1. Step 1: Write the proportion equation
   105.42 : 145.38 = 74.34 : x
2. Step 2: Convert to fraction form
   105.42/145.38 = 74.34/x
3. Step 3: Cross multiply
   105.42x = 145.38 × 74.34
4. Step 4: Simplify right side
   105.42x = 10,807.55
5. Step 5: Solve for x
   x = 10,807.55/105.42
6. Step 6: Final answer
   x = 102.52