Finding the Fourth Proportional to 39,892.18, 55,051.59 and 21,987.87

Step by Step Solution

1. Step 1: Write the proportion equation
   39,892.18 : 55,051.59 = 21,987.87 : x
2. Step 2: Convert to fraction form
   39,892.18/55,051.59 = 21,987.87/x
3. Step 3: Cross multiply
   39,892.18x = 55,051.59 × 21,987.87
4. Step 4: Simplify right side
   39,892.18x = 1,210,467,328.05
5. Step 5: Solve for x
   x = 1,210,467,328.05/39,892.18
6. Step 6: Final answer
   x = 30,343.47