Finding the Fourth Proportional to 89.30, 123.18 and 72.84

Step by Step Solution

1. Step 1: Write the proportion equation
   89.30 : 123.18 = 72.84 : x
2. Step 2: Convert to fraction form
   89.30/123.18 = 72.84/x
3. Step 3: Cross multiply
   89.30x = 123.18 × 72.84
4. Step 4: Simplify right side
   89.30x = 8,972.43
5. Step 5: Solve for x
   x = 8,972.43/89.30
6. Step 6: Final answer
   x = 100.48