Finding the Fourth Proportional to 31,046.21, 42,844.71 and 21,987.80

Step by Step Solution

1. Step 1: Write the proportion equation
   31,046.21 : 42,844.71 = 21,987.80 : x
2. Step 2: Convert to fraction form
   31,046.21/42,844.71 = 21,987.80/x
3. Step 3: Cross multiply
   31,046.21x = 42,844.71 × 21,987.80
4. Step 4: Simplify right side
   31,046.21x = 942,060,914.54
5. Step 5: Solve for x
   x = 942,060,914.54/31,046.21
6. Step 6: Final answer
   x = 30,343.83