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Finding the Fourth Proportional to 421.79, 580.82 and 412.20

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Solution

The fourth proportional to 421.79, 580.82 and 412.20 is: 567.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.79 : 580.82 = 412.20 : x
  2. Step 2: Convert to fraction form
    421.79/580.82 = 412.20/x
  3. Step 3: Cross multiply
    421.79x = 580.82 × 412.20
  4. Step 4: Simplify right side
    421.79x = 239,411.94
  5. Step 5: Solve for x
    x = 239,411.94/421.79
  6. Step 6: Final answer
    x = 567.62

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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.