Finding the Fourth Proportional to 13,978.34, 19,289.84 and 7,690.72

Step by Step Solution

1. Step 1: Write the proportion equation
   13,978.34 : 19,289.84 = 7,690.72 : x
2. Step 2: Convert to fraction form
   13,978.34/19,289.84 = 7,690.72/x
3. Step 3: Cross multiply
   13,978.34x = 19,289.84 × 7,690.72
4. Step 4: Simplify right side
   13,978.34x = 148,352,758.28
5. Step 5: Solve for x
   x = 148,352,758.28/13,978.34
6. Step 6: Final answer
   x = 10,613.05