Finding the Fourth Proportional to 72.18, 108.20 and 37.91

Step by Step Solution

1. Step 1: Write the proportion equation
   72.18 : 108.20 = 37.91 : x
2. Step 2: Convert to fraction form
   72.18/108.20 = 37.91/x
3. Step 3: Cross multiply
   72.18x = 108.20 × 37.91
4. Step 4: Simplify right side
   72.18x = 4,101.86
5. Step 5: Solve for x
   x = 4,101.86/72.18
6. Step 6: Final answer
   x = 56.83