Finding the Fourth Proportional to 72.45, 99.87 and 59.99

Step by Step Solution

1. Step 1: Write the proportion equation
   72.45 : 99.87 = 59.99 : x
2. Step 2: Convert to fraction form
   72.45/99.87 = 59.99/x
3. Step 3: Cross multiply
   72.45x = 99.87 × 59.99
4. Step 4: Simplify right side
   72.45x = 5,991.20
5. Step 5: Solve for x
   x = 5,991.20/72.45
6. Step 6: Final answer
   x = 82.69