Finding the Fourth Proportional to 99.86, 137.81 and 58.42

Step by Step Solution

1. Step 1: Write the proportion equation
   99.86 : 137.81 = 58.42 : x
2. Step 2: Convert to fraction form
   99.86/137.81 = 58.42/x
3. Step 3: Cross multiply
   99.86x = 137.81 × 58.42
4. Step 4: Simplify right side
   99.86x = 8,050.86
5. Step 5: Solve for x
   x = 8,050.86/99.86
6. Step 6: Final answer
   x = 80.62