Finding the Fourth Proportional to 61.16, 91.68 and 56.72

Step by Step Solution

1. Step 1: Write the proportion equation
   61.16 : 91.68 = 56.72 : x
2. Step 2: Convert to fraction form
   61.16/91.68 = 56.72/x
3. Step 3: Cross multiply
   61.16x = 91.68 × 56.72
4. Step 4: Simplify right side
   61.16x = 5,200.09
5. Step 5: Solve for x
   x = 5,200.09/61.16
6. Step 6: Final answer
   x = 85.02