Finding the Fourth Proportional to 72.91, 109.30 and 51.18

Step by Step Solution

1. Step 1: Write the proportion equation
   72.91 : 109.30 = 51.18 : x
2. Step 2: Convert to fraction form
   72.91/109.30 = 51.18/x
3. Step 3: Cross multiply
   72.91x = 109.30 × 51.18
4. Step 4: Simplify right side
   72.91x = 5,593.85
5. Step 5: Solve for x
   x = 5,593.85/72.91
6. Step 6: Final answer
   x = 76.73