Finding the Fourth Proportional to 13,978.72, 19,290.54 and 7,691.08

Step by Step Solution

1. Step 1: Write the proportion equation
   13,978.72 : 19,290.54 = 7,691.08 : x
2. Step 2: Convert to fraction form
   13,978.72/19,290.54 = 7,691.08/x
3. Step 3: Cross multiply
   13,978.72x = 19,290.54 × 7,691.08
4. Step 4: Simplify right side
   13,978.72x = 148,365,086.38
5. Step 5: Solve for x
   x = 148,365,086.38/13,978.72
6. Step 6: Final answer
   x = 10,613.64