Finding the Fourth Proportional to 1,213.71, 1,821.18 and 906.18

Step by Step Solution

1. Step 1: Write the proportion equation
   1,213.71 : 1,821.18 = 906.18 : x
2. Step 2: Convert to fraction form
   1,213.71/1,821.18 = 906.18/x
3. Step 3: Cross multiply
   1,213.71x = 1,821.18 × 906.18
4. Step 4: Simplify right side
   1,213.71x = 1,650,316.89
5. Step 5: Solve for x
   x = 1,650,316.89/1,213.71
6. Step 6: Final answer
   x = 1,359.73