Finding the Fourth Proportional to 89.99, 123.98 and 76.85

Step by Step Solution

1. Step 1: Write the proportion equation
   89.99 : 123.98 = 76.85 : x
2. Step 2: Convert to fraction form
   89.99/123.98 = 76.85/x
3. Step 3: Cross multiply
   89.99x = 123.98 × 76.85
4. Step 4: Simplify right side
   89.99x = 9,526.86
5. Step 5: Solve for x
   x = 9,526.86/89.99
6. Step 6: Final answer
   x = 105.87