Finding the Fourth Proportional to 72.09, 99.50 and 59.13

Step by Step Solution

1. Step 1: Write the proportion equation
   72.09 : 99.50 = 59.13 : x
2. Step 2: Convert to fraction form
   72.09/99.50 = 59.13/x
3. Step 3: Cross multiply
   72.09x = 99.50 × 59.13
4. Step 4: Simplify right side
   72.09x = 5,883.14
5. Step 5: Solve for x
   x = 5,883.14/72.09
6. Step 6: Final answer
   x = 81.61