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Finding the Fourth Proportional to 1,280.10, 1,920.06 and 402.78

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Solution

The fourth proportional to 1,280.10, 1,920.06 and 402.78 is: 604.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,280.10 : 1,920.06 = 402.78 : x
  2. Step 2: Convert to fraction form
    1,280.10/1,920.06 = 402.78/x
  3. Step 3: Cross multiply
    1,280.10x = 1,920.06 × 402.78
  4. Step 4: Simplify right side
    1,280.10x = 773,361.77
  5. Step 5: Solve for x
    x = 773,361.77/1,280.10
  6. Step 6: Final answer
    x = 604.14

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.