Finding the Fourth Proportional to 89.88, 123.93 and 83.40

Step by Step Solution

1. Step 1: Write the proportion equation
   89.88 : 123.93 = 83.40 : x
2. Step 2: Convert to fraction form
   89.88/123.93 = 83.40/x
3. Step 3: Cross multiply
   89.88x = 123.93 × 83.40
4. Step 4: Simplify right side
   89.88x = 10,335.76
5. Step 5: Solve for x
   x = 10,335.76/89.88
6. Step 6: Final answer
   x = 115.00