Finding the Fourth Proportional to 152.38, 210.28 and 100.72

Step by Step Solution

1. Step 1: Write the proportion equation
   152.38 : 210.28 = 100.72 : x
2. Step 2: Convert to fraction form
   152.38/210.28 = 100.72/x
3. Step 3: Cross multiply
   152.38x = 210.28 × 100.72
4. Step 4: Simplify right side
   152.38x = 21,179.40
5. Step 5: Solve for x
   x = 21,179.40/152.38
6. Step 6: Final answer
   x = 138.99