Finding the Fourth Proportional to 90.30, 124.72 and 81.10

Step by Step Solution

1. Step 1: Write the proportion equation
   90.30 : 124.72 = 81.10 : x
2. Step 2: Convert to fraction form
   90.30/124.72 = 81.10/x
3. Step 3: Cross multiply
   90.30x = 124.72 × 81.10
4. Step 4: Simplify right side
   90.30x = 10,114.79
5. Step 5: Solve for x
   x = 10,114.79/90.30
6. Step 6: Final answer
   x = 112.01