Finding the Fourth Proportional to 1,510.86, 2,084.40 and 921.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,510.86 : 2,084.40 = 921.30 : x
2. Step 2: Convert to fraction form
   1,510.86/2,084.40 = 921.30/x
3. Step 3: Cross multiply
   1,510.86x = 2,084.40 × 921.30
4. Step 4: Simplify right side
   1,510.86x = 1,920,357.72
5. Step 5: Solve for x
   x = 1,920,357.72/1,510.86
6. Step 6: Final answer
   x = 1,271.04