Finding the Fourth Proportional to 91.69, 137.53 and 61.31

Step by Step Solution

1. Step 1: Write the proportion equation
   91.69 : 137.53 = 61.31 : x
2. Step 2: Convert to fraction form
   91.69/137.53 = 61.31/x
3. Step 3: Cross multiply
   91.69x = 137.53 × 61.31
4. Step 4: Simplify right side
   91.69x = 8,431.96
5. Step 5: Solve for x
   x = 8,431.96/91.69
6. Step 6: Final answer
   x = 91.97