Finding the Fourth Proportional to 103.32, 141.72 and 90.36

Step by Step Solution

1. Step 1: Write the proportion equation
   103.32 : 141.72 = 90.36 : x
2. Step 2: Convert to fraction form
   103.32/141.72 = 90.36/x
3. Step 3: Cross multiply
   103.32x = 141.72 × 90.36
4. Step 4: Simplify right side
   103.32x = 12,805.82
5. Step 5: Solve for x
   x = 12,805.82/103.32
6. Step 6: Final answer
   x = 123.94