Finding the Fourth Proportional to 131.86, 181.94 and 100.79

Step by Step Solution

1. Step 1: Write the proportion equation
   131.86 : 181.94 = 100.79 : x
2. Step 2: Convert to fraction form
   131.86/181.94 = 100.79/x
3. Step 3: Cross multiply
   131.86x = 181.94 × 100.79
4. Step 4: Simplify right side
   131.86x = 18,337.23
5. Step 5: Solve for x
   x = 18,337.23/131.86
6. Step 6: Final answer
   x = 139.07