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Finding the Fourth Proportional to 420.56, 579.72 and 403.28

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Solution

The fourth proportional to 420.56, 579.72 and 403.28 is: 555.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.56 : 579.72 = 403.28 : x
  2. Step 2: Convert to fraction form
    420.56/579.72 = 403.28/x
  3. Step 3: Cross multiply
    420.56x = 579.72 × 403.28
  4. Step 4: Simplify right side
    420.56x = 233,789.48
  5. Step 5: Solve for x
    x = 233,789.48/420.56
  6. Step 6: Final answer
    x = 555.90

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.