Finding the Fourth Proportional to 105.34, 145.23 and 72.55

Step by Step Solution

1. Step 1: Write the proportion equation
   105.34 : 145.23 = 72.55 : x
2. Step 2: Convert to fraction form
   105.34/145.23 = 72.55/x
3. Step 3: Cross multiply
   105.34x = 145.23 × 72.55
4. Step 4: Simplify right side
   105.34x = 10,536.44
5. Step 5: Solve for x
   x = 10,536.44/105.34
6. Step 6: Final answer
   x = 100.02