Finding the Fourth Proportional to 7,890.86, 10,890.57 and 5,061.43

Step by Step Solution

1. Step 1: Write the proportion equation
   7,890.86 : 10,890.57 = 5,061.43 : x
2. Step 2: Convert to fraction form
   7,890.86/10,890.57 = 5,061.43/x
3. Step 3: Cross multiply
   7,890.86x = 10,890.57 × 5,061.43
4. Step 4: Simplify right side
   7,890.86x = 55,121,830.49
5. Step 5: Solve for x
   x = 55,121,830.49/7,890.86
6. Step 6: Final answer
   x = 6,985.53