Finding the Fourth Proportional to 209.72, 314.52 and 72.72

Step by Step Solution

1. Step 1: Write the proportion equation
   209.72 : 314.52 = 72.72 : x
2. Step 2: Convert to fraction form
   209.72/314.52 = 72.72/x
3. Step 3: Cross multiply
   209.72x = 314.52 × 72.72
4. Step 4: Simplify right side
   209.72x = 22,871.89
5. Step 5: Solve for x
   x = 22,871.89/209.72
6. Step 6: Final answer
   x = 109.06