Finding the Fourth Proportional to 85.99, 118.71 and 59.80

Step by Step Solution

1. Step 1: Write the proportion equation
   85.99 : 118.71 = 59.80 : x
2. Step 2: Convert to fraction form
   85.99/118.71 = 59.80/x
3. Step 3: Cross multiply
   85.99x = 118.71 × 59.80
4. Step 4: Simplify right side
   85.99x = 7,098.86
5. Step 5: Solve for x
   x = 7,098.86/85.99
6. Step 6: Final answer
   x = 82.55