Finding the Fourth Proportional to 31,091.34, 42,891.32 and 21,023.30

Step by Step Solution

1. Step 1: Write the proportion equation
   31,091.34 : 42,891.32 = 21,023.30 : x
2. Step 2: Convert to fraction form
   31,091.34/42,891.32 = 21,023.30/x
3. Step 3: Cross multiply
   31,091.34x = 42,891.32 × 21,023.30
4. Step 4: Simplify right side
   31,091.34x = 901,717,087.76
5. Step 5: Solve for x
   x = 901,717,087.76/31,091.34
6. Step 6: Final answer
   x = 29,002.19