Finding the Fourth Proportional to 9,513.78, 13,128.78 and 5,264.74

Step by Step Solution

1. Step 1: Write the proportion equation
   9,513.78 : 13,128.78 = 5,264.74 : x
2. Step 2: Convert to fraction form
   9,513.78/13,128.78 = 5,264.74/x
3. Step 3: Cross multiply
   9,513.78x = 13,128.78 × 5,264.74
4. Step 4: Simplify right side
   9,513.78x = 69,119,613.22
5. Step 5: Solve for x
   x = 69,119,613.22/9,513.78
6. Step 6: Final answer
   x = 7,265.21