Finding the Fourth Proportional to 66,488.72, 91,743.12 and 39,630.72

Step by Step Solution

1. Step 1: Write the proportion equation
   66,488.72 : 91,743.12 = 39,630.72 : x
2. Step 2: Convert to fraction form
   66,488.72/91,743.12 = 39,630.72/x
3. Step 3: Cross multiply
   66,488.72x = 91,743.12 × 39,630.72
4. Step 4: Simplify right side
   66,488.72x = 3,635,845,900.65
5. Step 5: Solve for x
   x = 3,635,845,900.65/66,488.72
6. Step 6: Final answer
   x = 54,683.65