Finding the Fourth Proportional to 156.06, 215.31 and 100.83

Step by Step Solution

1. Step 1: Write the proportion equation
   156.06 : 215.31 = 100.83 : x
2. Step 2: Convert to fraction form
   156.06/215.31 = 100.83/x
3. Step 3: Cross multiply
   156.06x = 215.31 × 100.83
4. Step 4: Simplify right side
   156.06x = 21,709.71
5. Step 5: Solve for x
   x = 21,709.71/156.06
6. Step 6: Final answer
   x = 139.11