Finding the Fourth Proportional to 89.34, 123.12 and 83.76

Step by Step Solution

1. Step 1: Write the proportion equation
   89.34 : 123.12 = 83.76 : x
2. Step 2: Convert to fraction form
   89.34/123.12 = 83.76/x
3. Step 3: Cross multiply
   89.34x = 123.12 × 83.76
4. Step 4: Simplify right side
   89.34x = 10,312.53
5. Step 5: Solve for x
   x = 10,312.53/89.34
6. Step 6: Final answer
   x = 115.43