Finding the Fourth Proportional to 91.69, 137.59 and 57.49

Step by Step Solution

1. Step 1: Write the proportion equation
   91.69 : 137.59 = 57.49 : x
2. Step 2: Convert to fraction form
   91.69/137.59 = 57.49/x
3. Step 3: Cross multiply
   91.69x = 137.59 × 57.49
4. Step 4: Simplify right side
   91.69x = 7,909.56
5. Step 5: Solve for x
   x = 7,909.56/91.69
6. Step 6: Final answer
   x = 86.27