Finding the Fourth Proportional to 89.40, 123.83 and 83.53

Step by Step Solution

1. Step 1: Write the proportion equation
   89.40 : 123.83 = 83.53 : x
2. Step 2: Convert to fraction form
   89.40/123.83 = 83.53/x
3. Step 3: Cross multiply
   89.40x = 123.83 × 83.53
4. Step 4: Simplify right side
   89.40x = 10,343.57
5. Step 5: Solve for x
   x = 10,343.57/89.40
6. Step 6: Final answer
   x = 115.70