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Finding the Fourth Proportional to 420, 579.68 and 401.55

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Solution

The fourth proportional to 420, 579.68 and 401.55 is: 554.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    420 : 579.68 = 401.55 : x
  2. Step 2: Convert to fraction form
    420/579.68 = 401.55/x
  3. Step 3: Cross multiply
    420x = 579.68 × 401.55
  4. Step 4: Simplify right side
    420x = 232,768.50
  5. Step 5: Solve for x
    x = 232,768.50/420
  6. Step 6: Final answer
    x = 554.21

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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.