Finding the Fourth Proportional to 109.38, 150.90 and 72.50

Step by Step Solution

1. Step 1: Write the proportion equation
   109.38 : 150.90 = 72.50 : x
2. Step 2: Convert to fraction form
   109.38/150.90 = 72.50/x
3. Step 3: Cross multiply
   109.38x = 150.90 × 72.50
4. Step 4: Simplify right side
   109.38x = 10,939.22
5. Step 5: Solve for x
   x = 10,939.22/109.38
6. Step 6: Final answer
   x = 100.01