Finding the Fourth Proportional to 13,087.72, 19,631.38 and 5,291

Step by Step Solution

1. Step 1: Write the proportion equation
   13,087.72 : 19,631.38 = 5,291 : x
2. Step 2: Convert to fraction form
   13,087.72/19,631.38 = 5,291/x
3. Step 3: Cross multiply
   13,087.72x = 19,631.38 × 5,291
4. Step 4: Simplify right side
   13,087.72x = 103,869,631.58
5. Step 5: Solve for x
   x = 103,869,631.58/13,087.72
6. Step 6: Final answer
   x = 7,936.42