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Finding the Fourth Proportional to 391.71, 533.82 and 390.27

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Solution

The fourth proportional to 391.71, 533.82 and 390.27 is: 531.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.71 : 533.82 = 390.27 : x
  2. Step 2: Convert to fraction form
    391.71/533.82 = 390.27/x
  3. Step 3: Cross multiply
    391.71x = 533.82 × 390.27
  4. Step 4: Simplify right side
    391.71x = 208,333.93
  5. Step 5: Solve for x
    x = 208,333.93/391.71
  6. Step 6: Final answer
    x = 531.86

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Why These Related Problems?

These problems maintain the same ratio (1.36) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.