Finding the Fourth Proportional to 100.85, 139.16 and 59.42

Step by Step Solution

1. Step 1: Write the proportion equation
   100.85 : 139.16 = 59.42 : x
2. Step 2: Convert to fraction form
   100.85/139.16 = 59.42/x
3. Step 3: Cross multiply
   100.85x = 139.16 × 59.42
4. Step 4: Simplify right side
   100.85x = 8,268.34
5. Step 5: Solve for x
   x = 8,268.34/100.85
6. Step 6: Final answer
   x = 81.99