Finding the Fourth Proportional to 99.31, 136.76 and 90.52

Step by Step Solution

1. Step 1: Write the proportion equation
   99.31 : 136.76 = 90.52 : x
2. Step 2: Convert to fraction form
   99.31/136.76 = 90.52/x
3. Step 3: Cross multiply
   99.31x = 136.76 × 90.52
4. Step 4: Simplify right side
   99.31x = 12,379.52
5. Step 5: Solve for x
   x = 12,379.52/99.31
6. Step 6: Final answer
   x = 124.66