Finding the Fourth Proportional to 71.98, 99.17 and 56.49

Step by Step Solution

1. Step 1: Write the proportion equation
   71.98 : 99.17 = 56.49 : x
2. Step 2: Convert to fraction form
   71.98/99.17 = 56.49/x
3. Step 3: Cross multiply
   71.98x = 99.17 × 56.49
4. Step 4: Simplify right side
   71.98x = 5,601.67
5. Step 5: Solve for x
   x = 5,601.67/71.98
6. Step 6: Final answer
   x = 77.83