Finding the Fourth Proportional to 100.05, 137.99 and 72.60

Step by Step Solution

1. Step 1: Write the proportion equation
   100.05 : 137.99 = 72.60 : x
2. Step 2: Convert to fraction form
   100.05/137.99 = 72.60/x
3. Step 3: Cross multiply
   100.05x = 137.99 × 72.60
4. Step 4: Simplify right side
   100.05x = 10,017.71
5. Step 5: Solve for x
   x = 10,017.71/100.05
6. Step 6: Final answer
   x = 100.13