Finding the Fourth Proportional to 131.21, 196.61 and 100.63

Step by Step Solution

1. Step 1: Write the proportion equation
   131.21 : 196.61 = 100.63 : x
2. Step 2: Convert to fraction form
   131.21/196.61 = 100.63/x
3. Step 3: Cross multiply
   131.21x = 196.61 × 100.63
4. Step 4: Simplify right side
   131.21x = 19,784.86
5. Step 5: Solve for x
   x = 19,784.86/131.21
6. Step 6: Final answer
   x = 150.79