Finding the Fourth Proportional to 90.45, 124.83 and 62.91

Step by Step Solution

1. Step 1: Write the proportion equation
   90.45 : 124.83 = 62.91 : x
2. Step 2: Convert to fraction form
   90.45/124.83 = 62.91/x
3. Step 3: Cross multiply
   90.45x = 124.83 × 62.91
4. Step 4: Simplify right side
   90.45x = 7,852.12
5. Step 5: Solve for x
   x = 7,852.12/90.45
6. Step 6: Final answer
   x = 86.82