Finding the Fourth Proportional to 71.99, 99.25 and 55.42

Step by Step Solution

1. Step 1: Write the proportion equation
   71.99 : 99.25 = 55.42 : x
2. Step 2: Convert to fraction form
   71.99/99.25 = 55.42/x
3. Step 3: Cross multiply
   71.99x = 99.25 × 55.42
4. Step 4: Simplify right side
   71.99x = 5,500.16
5. Step 5: Solve for x
   x = 5,500.16/71.99
6. Step 6: Final answer
   x = 76.40