Finding the Fourth Proportional to 89.38, 123.31 and 61.74

Step by Step Solution

1. Step 1: Write the proportion equation
   89.38 : 123.31 = 61.74 : x
2. Step 2: Convert to fraction form
   89.38/123.31 = 61.74/x
3. Step 3: Cross multiply
   89.38x = 123.31 × 61.74
4. Step 4: Simplify right side
   89.38x = 7,613.16
5. Step 5: Solve for x
   x = 7,613.16/89.38
6. Step 6: Final answer
   x = 85.18