Finding the Fourth Proportional to 31,045.21, 42,843.33 and 21,986.80

Step by Step Solution

1. Step 1: Write the proportion equation
   31,045.21 : 42,843.33 = 21,986.80 : x
2. Step 2: Convert to fraction form
   31,045.21/42,843.33 = 21,986.80/x
3. Step 3: Cross multiply
   31,045.21x = 42,843.33 × 21,986.80
4. Step 4: Simplify right side
   31,045.21x = 941,987,620.94
5. Step 5: Solve for x
   x = 941,987,620.94/31,045.21
6. Step 6: Final answer
   x = 30,342.45