Finding the Fourth Proportional to 71.86, 107.82 and 42.98

Step by Step Solution

1. Step 1: Write the proportion equation
   71.86 : 107.82 = 42.98 : x
2. Step 2: Convert to fraction form
   71.86/107.82 = 42.98/x
3. Step 3: Cross multiply
   71.86x = 107.82 × 42.98
4. Step 4: Simplify right side
   71.86x = 4,634.10
5. Step 5: Solve for x
   x = 4,634.10/71.86
6. Step 6: Final answer
   x = 64.49