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Finding the Fourth Proportional to 1,281.52, 1,921.72 and 403.78

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Solution

The fourth proportional to 1,281.52, 1,921.72 and 403.78 is: 605.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,281.52 : 1,921.72 = 403.78 : x
  2. Step 2: Convert to fraction form
    1,281.52/1,921.72 = 403.78/x
  3. Step 3: Cross multiply
    1,281.52x = 1,921.72 × 403.78
  4. Step 4: Simplify right side
    1,281.52x = 775,952.10
  5. Step 5: Solve for x
    x = 775,952.10/1,281.52
  6. Step 6: Final answer
    x = 605.49

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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.