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Finding the Fourth Proportional to 1,280.42, 1,920.09 and 402.68

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Solution

The fourth proportional to 1,280.42, 1,920.09 and 402.68 is: 603.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,280.42 : 1,920.09 = 402.68 : x
  2. Step 2: Convert to fraction form
    1,280.42/1,920.09 = 402.68/x
  3. Step 3: Cross multiply
    1,280.42x = 1,920.09 × 402.68
  4. Step 4: Simplify right side
    1,280.42x = 773,181.84
  5. Step 5: Solve for x
    x = 773,181.84/1,280.42
  6. Step 6: Final answer
    x = 603.85

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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.