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Finding the Fourth Proportional to 420.45, 579.82 and 387.35

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Solution

The fourth proportional to 420.45, 579.82 and 387.35 is: 534.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.45 : 579.82 = 387.35 : x
  2. Step 2: Convert to fraction form
    420.45/579.82 = 387.35/x
  3. Step 3: Cross multiply
    420.45x = 579.82 × 387.35
  4. Step 4: Simplify right side
    420.45x = 224,593.28
  5. Step 5: Solve for x
    x = 224,593.28/420.45
  6. Step 6: Final answer
    x = 534.17

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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.