Finding the Fourth Proportional to 156.17, 215.27 and 100.83

Step by Step Solution

1. Step 1: Write the proportion equation
   156.17 : 215.27 = 100.83 : x
2. Step 2: Convert to fraction form
   156.17/215.27 = 100.83/x
3. Step 3: Cross multiply
   156.17x = 215.27 × 100.83
4. Step 4: Simplify right side
   156.17x = 21,705.67
5. Step 5: Solve for x
   x = 21,705.67/156.17
6. Step 6: Final answer
   x = 138.99