Finding the Fourth Proportional to 9,890.41, 13,649.34 and 5,642.77

Step by Step Solution

1. Step 1: Write the proportion equation
   9,890.41 : 13,649.34 = 5,642.77 : x
2. Step 2: Convert to fraction form
   9,890.41/13,649.34 = 5,642.77/x
3. Step 3: Cross multiply
   9,890.41x = 13,649.34 × 5,642.77
4. Step 4: Simplify right side
   9,890.41x = 77,020,086.27
5. Step 5: Solve for x
   x = 77,020,086.27/9,890.41
6. Step 6: Final answer
   x = 7,787.35