Finding the Fourth Proportional to 155.69, 214.89 and 100.43

Step by Step Solution

1. Step 1: Write the proportion equation
   155.69 : 214.89 = 100.43 : x
2. Step 2: Convert to fraction form
   155.69/214.89 = 100.43/x
3. Step 3: Cross multiply
   155.69x = 214.89 × 100.43
4. Step 4: Simplify right side
   155.69x = 21,580.33
5. Step 5: Solve for x
   x = 21,580.33/155.69
6. Step 6: Final answer
   x = 138.62