Finding the Fourth Proportional to 13,045.39, 19,567.76 and 7,128.02

Step by Step Solution

1. Step 1: Write the proportion equation
   13,045.39 : 19,567.76 = 7,128.02 : x
2. Step 2: Convert to fraction form
   13,045.39/19,567.76 = 7,128.02/x
3. Step 3: Cross multiply
   13,045.39x = 19,567.76 × 7,128.02
4. Step 4: Simplify right side
   13,045.39x = 139,479,397.91
5. Step 5: Solve for x
   x = 139,479,397.91/13,045.39
6. Step 6: Final answer
   x = 10,691.86