Finding the Fourth Proportional to 90.31, 124.73 and 61.15

Step by Step Solution

1. Step 1: Write the proportion equation
   90.31 : 124.73 = 61.15 : x
2. Step 2: Convert to fraction form
   90.31/124.73 = 61.15/x
3. Step 3: Cross multiply
   90.31x = 124.73 × 61.15
4. Step 4: Simplify right side
   90.31x = 7,627.70
5. Step 5: Solve for x
   x = 7,627.70/90.31
6. Step 6: Final answer
   x = 84.46