Finding the Fourth Proportional to 155.82, 215.18 and 100.69

Step by Step Solution

1. Step 1: Write the proportion equation
   155.82 : 215.18 = 100.69 : x
2. Step 2: Convert to fraction form
   155.82/215.18 = 100.69/x
3. Step 3: Cross multiply
   155.82x = 215.18 × 100.69
4. Step 4: Simplify right side
   155.82x = 21,666.47
5. Step 5: Solve for x
   x = 21,666.47/155.82
6. Step 6: Final answer
   x = 139.05