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Finding the Fourth Proportional to 451.20, 677.28 and 428.16

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Solution

The fourth proportional to 451.20, 677.28 and 428.16 is: 642.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    451.20 : 677.28 = 428.16 : x
  2. Step 2: Convert to fraction form
    451.20/677.28 = 428.16/x
  3. Step 3: Cross multiply
    451.20x = 677.28 × 428.16
  4. Step 4: Simplify right side
    451.20x = 289,984.20
  5. Step 5: Solve for x
    x = 289,984.20/451.20
  6. Step 6: Final answer
    x = 642.70

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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.