Finding the Fourth Proportional to 11,587.31, 17,376.47 and 3,987.15

Step by Step Solution

1. Step 1: Write the proportion equation
   11,587.31 : 17,376.47 = 3,987.15 : x
2. Step 2: Convert to fraction form
   11,587.31/17,376.47 = 3,987.15/x
3. Step 3: Cross multiply
   11,587.31x = 17,376.47 × 3,987.15
4. Step 4: Simplify right side
   11,587.31x = 69,282,592.36
5. Step 5: Solve for x
   x = 69,282,592.36/11,587.31
6. Step 6: Final answer
   x = 5,979.18