Finding the Fourth Proportional to 1,581.50, 2,181.72 and 1,021.70

Step by Step Solution

1. Step 1: Write the proportion equation
   1,581.50 : 2,181.72 = 1,021.70 : x
2. Step 2: Convert to fraction form
   1,581.50/2,181.72 = 1,021.70/x
3. Step 3: Cross multiply
   1,581.50x = 2,181.72 × 1,021.70
4. Step 4: Simplify right side
   1,581.50x = 2,229,063.32
5. Step 5: Solve for x
   x = 2,229,063.32/1,581.50
6. Step 6: Final answer
   x = 1,409.46