Finding the Fourth Proportional to 9,128.51, 12,599.63 and 5,151.90

Step by Step Solution

1. Step 1: Write the proportion equation
   9,128.51 : 12,599.63 = 5,151.90 : x
2. Step 2: Convert to fraction form
   9,128.51/12,599.63 = 5,151.90/x
3. Step 3: Cross multiply
   9,128.51x = 12,599.63 × 5,151.90
4. Step 4: Simplify right side
   9,128.51x = 64,912,008.04
5. Step 5: Solve for x
   x = 64,912,008.04/9,128.51
6. Step 6: Final answer
   x = 7,110.91