Finding the Fourth Proportional to 100.69, 138.89 and 59.23

Step by Step Solution

1. Step 1: Write the proportion equation
   100.69 : 138.89 = 59.23 : x
2. Step 2: Convert to fraction form
   100.69/138.89 = 59.23/x
3. Step 3: Cross multiply
   100.69x = 138.89 × 59.23
4. Step 4: Simplify right side
   100.69x = 8,226.61
5. Step 5: Solve for x
   x = 8,226.61/100.69
6. Step 6: Final answer
   x = 81.70