Finding the Fourth Proportional to 31,101.84, 42,886.66 and 21,012.76

Step by Step Solution

1. Step 1: Write the proportion equation
   31,101.84 : 42,886.66 = 21,012.76 : x
2. Step 2: Convert to fraction form
   31,101.84/42,886.66 = 21,012.76/x
3. Step 3: Cross multiply
   31,101.84x = 42,886.66 × 21,012.76
4. Step 4: Simplify right side
   31,101.84x = 901,167,093.78
5. Step 5: Solve for x
   x = 901,167,093.78/31,101.84
6. Step 6: Final answer
   x = 28,974.72