Finding the Fourth Proportional to 1,575.91, 2,174.72 and 912.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,575.91 : 2,174.72 = 912.88 : x
2. Step 2: Convert to fraction form
   1,575.91/2,174.72 = 912.88/x
3. Step 3: Cross multiply
   1,575.91x = 2,174.72 × 912.88
4. Step 4: Simplify right side
   1,575.91x = 1,985,258.39
5. Step 5: Solve for x
   x = 1,985,258.39/1,575.91
6. Step 6: Final answer
   x = 1,259.75