Finding the Fourth Proportional to 127.39, 175.78 and 72.12

Step by Step Solution

1. Step 1: Write the proportion equation
   127.39 : 175.78 = 72.12 : x
2. Step 2: Convert to fraction form
   127.39/175.78 = 72.12/x
3. Step 3: Cross multiply
   127.39x = 175.78 × 72.12
4. Step 4: Simplify right side
   127.39x = 12,677.25
5. Step 5: Solve for x
   x = 12,677.25/127.39
6. Step 6: Final answer
   x = 99.52