Finding the Fourth Proportional to 61.61, 91.71 and 61.30

Step by Step Solution

1. Step 1: Write the proportion equation
   61.61 : 91.71 = 61.30 : x
2. Step 2: Convert to fraction form
   61.61/91.71 = 61.30/x
3. Step 3: Cross multiply
   61.61x = 91.71 × 61.30
4. Step 4: Simplify right side
   61.61x = 5,621.59
5. Step 5: Solve for x
   x = 5,621.59/61.61
6. Step 6: Final answer
   x = 91.25