Finding the Fourth Proportional to 109.31, 150.98 and 89.69

Step by Step Solution

1. Step 1: Write the proportion equation
   109.31 : 150.98 = 89.69 : x
2. Step 2: Convert to fraction form
   109.31/150.98 = 89.69/x
3. Step 3: Cross multiply
   109.31x = 150.98 × 89.69
4. Step 4: Simplify right side
   109.31x = 13,540.19
5. Step 5: Solve for x
   x = 13,540.19/109.31
6. Step 6: Final answer
   x = 123.88