Finding the Fourth Proportional to 1,383.31, 1,907.71 and 916.75

Step by Step Solution

1. Step 1: Write the proportion equation
   1,383.31 : 1,907.71 = 916.75 : x
2. Step 2: Convert to fraction form
   1,383.31/1,907.71 = 916.75/x
3. Step 3: Cross multiply
   1,383.31x = 1,907.71 × 916.75
4. Step 4: Simplify right side
   1,383.31x = 1,748,893.14
5. Step 5: Solve for x
   x = 1,748,893.14/1,383.31
6. Step 6: Final answer
   x = 1,264.28