Finding the Fourth Proportional to 20,742.42, 31,113.56 and 5,160.05

Step by Step Solution

1. Step 1: Write the proportion equation
   20,742.42 : 31,113.56 = 5,160.05 : x
2. Step 2: Convert to fraction form
   20,742.42/31,113.56 = 5,160.05/x
3. Step 3: Cross multiply
   20,742.42x = 31,113.56 × 5,160.05
4. Step 4: Simplify right side
   20,742.42x = 160,547,382.61
5. Step 5: Solve for x
   x = 160,547,382.61/20,742.42
6. Step 6: Final answer
   x = 7,740.05