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Finding the Fourth Proportional to 387.82, 580.29 and 285.40

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Solution

The fourth proportional to 387.82, 580.29 and 285.40 is: 427.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.82 : 580.29 = 285.40 : x
  2. Step 2: Convert to fraction form
    387.82/580.29 = 285.40/x
  3. Step 3: Cross multiply
    387.82x = 580.29 × 285.40
  4. Step 4: Simplify right side
    387.82x = 165,614.77
  5. Step 5: Solve for x
    x = 165,614.77/387.82
  6. Step 6: Final answer
    x = 427.04

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.