Finding the Fourth Proportional to 100.82, 151.75 and 90.88

Step by Step Solution

1. Step 1: Write the proportion equation
   100.82 : 151.75 = 90.88 : x
2. Step 2: Convert to fraction form
   100.82/151.75 = 90.88/x
3. Step 3: Cross multiply
   100.82x = 151.75 × 90.88
4. Step 4: Simplify right side
   100.82x = 13,789.83
5. Step 5: Solve for x
   x = 13,789.83/100.82
6. Step 6: Final answer
   x = 136.78