Finding the Fourth Proportional to 149.84, 206.72 and 100.72

Step by Step Solution

1. Step 1: Write the proportion equation
   149.84 : 206.72 = 100.72 : x
2. Step 2: Convert to fraction form
   149.84/206.72 = 100.72/x
3. Step 3: Cross multiply
   149.84x = 206.72 × 100.72
4. Step 4: Simplify right side
   149.84x = 20,820.84
5. Step 5: Solve for x
   x = 20,820.84/149.84
6. Step 6: Final answer
   x = 138.95