Finding the Fourth Proportional to 72.74, 100.31 and 56.06

Step by Step Solution

1. Step 1: Write the proportion equation
   72.74 : 100.31 = 56.06 : x
2. Step 2: Convert to fraction form
   72.74/100.31 = 56.06/x
3. Step 3: Cross multiply
   72.74x = 100.31 × 56.06
4. Step 4: Simplify right side
   72.74x = 5,623.38
5. Step 5: Solve for x
   x = 5,623.38/72.74
6. Step 6: Final answer
   x = 77.31