Finding the Fourth Proportional to 72.48, 108.73 and 55.40

Step by Step Solution

1. Step 1: Write the proportion equation
   72.48 : 108.73 = 55.40 : x
2. Step 2: Convert to fraction form
   72.48/108.73 = 55.40/x
3. Step 3: Cross multiply
   72.48x = 108.73 × 55.40
4. Step 4: Simplify right side
   72.48x = 6,022.86
5. Step 5: Solve for x
   x = 6,022.86/72.48
6. Step 6: Final answer
   x = 83.09