Finding the Fourth Proportional to 100.32, 138.50 and 72.76

Step by Step Solution

1. Step 1: Write the proportion equation
   100.32 : 138.50 = 72.76 : x
2. Step 2: Convert to fraction form
   100.32/138.50 = 72.76/x
3. Step 3: Cross multiply
   100.32x = 138.50 × 72.76
4. Step 4: Simplify right side
   100.32x = 10,077.26
5. Step 5: Solve for x
   x = 10,077.26/100.32
6. Step 6: Final answer
   x = 100.45