Finding the Fourth Proportional to 156.06, 215.33 and 100.89

Step by Step Solution

1. Step 1: Write the proportion equation
   156.06 : 215.33 = 100.89 : x
2. Step 2: Convert to fraction form
   156.06/215.33 = 100.89/x
3. Step 3: Cross multiply
   156.06x = 215.33 × 100.89
4. Step 4: Simplify right side
   156.06x = 21,724.14
5. Step 5: Solve for x
   x = 21,724.14/156.06
6. Step 6: Final answer
   x = 139.20