Finding the Fourth Proportional to 89.76, 123.83 and 57.00

Step by Step Solution

1. Step 1: Write the proportion equation
   89.76 : 123.83 = 57.00 : x
2. Step 2: Convert to fraction form
   89.76/123.83 = 57.00/x
3. Step 3: Cross multiply
   89.76x = 123.83 × 57.00
4. Step 4: Simplify right side
   89.76x = 7,057.41
5. Step 5: Solve for x
   x = 7,057.41/89.76
6. Step 6: Final answer
   x = 78.63