Finding the Fourth Proportional to 72.98, 109.23 and 71.42

Step by Step Solution

1. Step 1: Write the proportion equation
   72.98 : 109.23 = 71.42 : x
2. Step 2: Convert to fraction form
   72.98/109.23 = 71.42/x
3. Step 3: Cross multiply
   72.98x = 109.23 × 71.42
4. Step 4: Simplify right side
   72.98x = 7,801.21
5. Step 5: Solve for x
   x = 7,801.21/72.98
6. Step 6: Final answer
   x = 106.90