Finding the Fourth Proportional to 40,136.72, 55,388.05 and 21,987.29

Step by Step Solution

1. Step 1: Write the proportion equation
   40,136.72 : 55,388.05 = 21,987.29 : x
2. Step 2: Convert to fraction form
   40,136.72/55,388.05 = 21,987.29/x
3. Step 3: Cross multiply
   40,136.72x = 55,388.05 × 21,987.29
4. Step 4: Simplify right side
   40,136.72x = 1,217,833,117.88
5. Step 5: Solve for x
   x = 1,217,833,117.88/40,136.72
6. Step 6: Final answer
   x = 30,342.12