Finding the Fourth Proportional to 128.27, 176.96 and 100.53

Step by Step Solution

1. Step 1: Write the proportion equation
   128.27 : 176.96 = 100.53 : x
2. Step 2: Convert to fraction form
   128.27/176.96 = 100.53/x
3. Step 3: Cross multiply
   128.27x = 176.96 × 100.53
4. Step 4: Simplify right side
   128.27x = 17,789.79
5. Step 5: Solve for x
   x = 17,789.79/128.27
6. Step 6: Final answer
   x = 138.69