Finding the Fourth Proportional to 1,109.66, 1,664.89 and 379.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,109.66 : 1,664.89 = 379.31 : x
2. Step 2: Convert to fraction form
   1,109.66/1,664.89 = 379.31/x
3. Step 3: Cross multiply
   1,109.66x = 1,664.89 × 379.31
4. Step 4: Simplify right side
   1,109.66x = 631,509.43
5. Step 5: Solve for x
   x = 631,509.43/1,109.66
6. Step 6: Final answer
   x = 569.10