Finding the Fourth Proportional to 1,573.84, 2,172.15 and 911.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,573.84 : 2,172.15 = 911.10 : x
2. Step 2: Convert to fraction form
   1,573.84/2,172.15 = 911.10/x
3. Step 3: Cross multiply
   1,573.84x = 2,172.15 × 911.10
4. Step 4: Simplify right side
   1,573.84x = 1,979,045.87
5. Step 5: Solve for x
   x = 1,979,045.87/1,573.84
6. Step 6: Final answer
   x = 1,257.46