Finding the Fourth Proportional to 90.50, 124.83 and 57.72

Step by Step Solution

1. Step 1: Write the proportion equation
   90.50 : 124.83 = 57.72 : x
2. Step 2: Convert to fraction form
   90.50/124.83 = 57.72/x
3. Step 3: Cross multiply
   90.50x = 124.83 × 57.72
4. Step 4: Simplify right side
   90.50x = 7,205.19
5. Step 5: Solve for x
   x = 7,205.19/90.50
6. Step 6: Final answer
   x = 79.62