Finding the Fourth Proportional to 1,210.72, 1,668.96 and 998.32

Step by Step Solution

1. Step 1: Write the proportion equation
   1,210.72 : 1,668.96 = 998.32 : x
2. Step 2: Convert to fraction form
   1,210.72/1,668.96 = 998.32/x
3. Step 3: Cross multiply
   1,210.72x = 1,668.96 × 998.32
4. Step 4: Simplify right side
   1,210.72x = 1,666,156.15
5. Step 5: Solve for x
   x = 1,666,156.15/1,210.72
6. Step 6: Final answer
   x = 1,376.17