Finding the Fourth Proportional to 156.72, 234.83 and 139.91

Step by Step Solution

1. Step 1: Write the proportion equation
   156.72 : 234.83 = 139.91 : x
2. Step 2: Convert to fraction form
   156.72/234.83 = 139.91/x
3. Step 3: Cross multiply
   156.72x = 234.83 × 139.91
4. Step 4: Simplify right side
   156.72x = 32,853.19
5. Step 5: Solve for x
   x = 32,853.19/156.72
6. Step 6: Final answer
   x = 209.63