Finding the Fourth Proportional to 7,345.99, 10,128.95 and 5,109.78

Step by Step Solution

1. Step 1: Write the proportion equation
   7,345.99 : 10,128.95 = 5,109.78 : x
2. Step 2: Convert to fraction form
   7,345.99/10,128.95 = 5,109.78/x
3. Step 3: Cross multiply
   7,345.99x = 10,128.95 × 5,109.78
4. Step 4: Simplify right side
   7,345.99x = 51,756,737.73
5. Step 5: Solve for x
   x = 51,756,737.73/7,345.99
6. Step 6: Final answer
   x = 7,045.58