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Finding the Fourth Proportional to 420.36, 579.88 and 280.44

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Solution

The fourth proportional to 420.36, 579.88 and 280.44 is: 386.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.36 : 579.88 = 280.44 : x
  2. Step 2: Convert to fraction form
    420.36/579.88 = 280.44/x
  3. Step 3: Cross multiply
    420.36x = 579.88 × 280.44
  4. Step 4: Simplify right side
    420.36x = 162,621.55
  5. Step 5: Solve for x
    x = 162,621.55/420.36
  6. Step 6: Final answer
    x = 386.86

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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.