Finding the Fourth Proportional to 196.61, 271.01 and 155.10

Step by Step Solution

1. Step 1: Write the proportion equation
   196.61 : 271.01 = 155.10 : x
2. Step 2: Convert to fraction form
   196.61/271.01 = 155.10/x
3. Step 3: Cross multiply
   196.61x = 271.01 × 155.10
4. Step 4: Simplify right side
   196.61x = 42,032.88
5. Step 5: Solve for x
   x = 42,032.88/196.61
6. Step 6: Final answer
   x = 213.79