Finding the Fourth Proportional to 90.30, 124.56 and 61.18

Step by Step Solution

1. Step 1: Write the proportion equation
   90.30 : 124.56 = 61.18 : x
2. Step 2: Convert to fraction form
   90.30/124.56 = 61.18/x
3. Step 3: Cross multiply
   90.30x = 124.56 × 61.18
4. Step 4: Simplify right side
   90.30x = 7,620.58
5. Step 5: Solve for x
   x = 7,620.58/90.30
6. Step 6: Final answer
   x = 84.39