Finding the Fourth Proportional to 72.79, 109.01 and 51.15

Step by Step Solution

1. Step 1: Write the proportion equation
   72.79 : 109.01 = 51.15 : x
2. Step 2: Convert to fraction form
   72.79/109.01 = 51.15/x
3. Step 3: Cross multiply
   72.79x = 109.01 × 51.15
4. Step 4: Simplify right side
   72.79x = 5,575.86
5. Step 5: Solve for x
   x = 5,575.86/72.79
6. Step 6: Final answer
   x = 76.60