Finding the Fourth Proportional to 103.88, 143.00 and 89.98

Step by Step Solution

1. Step 1: Write the proportion equation
   103.88 : 143.00 = 89.98 : x
2. Step 2: Convert to fraction form
   103.88/143.00 = 89.98/x
3. Step 3: Cross multiply
   103.88x = 143.00 × 89.98
4. Step 4: Simplify right side
   103.88x = 12,866.69
5. Step 5: Solve for x
   x = 12,866.69/103.88
6. Step 6: Final answer
   x = 123.87