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Finding the Fourth Proportional to 387.96, 534.42 and 289.55

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Solution

The fourth proportional to 387.96, 534.42 and 289.55 is: 398.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.96 : 534.42 = 289.55 : x
  2. Step 2: Convert to fraction form
    387.96/534.42 = 289.55/x
  3. Step 3: Cross multiply
    387.96x = 534.42 × 289.55
  4. Step 4: Simplify right side
    387.96x = 154,738.64
  5. Step 5: Solve for x
    x = 154,738.64/387.96
  6. Step 6: Final answer
    x = 398.85

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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.