Finding the Fourth Proportional to 20,987.19, 31,479.78 and 5,192.16

Step by Step Solution

1. Step 1: Write the proportion equation
   20,987.19 : 31,479.78 = 5,192.16 : x
2. Step 2: Convert to fraction form
   20,987.19/31,479.78 = 5,192.16/x
3. Step 3: Cross multiply
   20,987.19x = 31,479.78 × 5,192.16
4. Step 4: Simplify right side
   20,987.19x = 163,448,054.52
5. Step 5: Solve for x
   x = 163,448,054.52/20,987.19
6. Step 6: Final answer
   x = 7,787.99