Finding the Fourth Proportional to 1,554.96, 2,145.71 and 916.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,554.96 : 2,145.71 = 916.80 : x
2. Step 2: Convert to fraction form
   1,554.96/2,145.71 = 916.80/x
3. Step 3: Cross multiply
   1,554.96x = 2,145.71 × 916.80
4. Step 4: Simplify right side
   1,554.96x = 1,967,181.17
5. Step 5: Solve for x
   x = 1,967,181.17/1,554.96
6. Step 6: Final answer
   x = 1,265.10