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Finding the Fourth Proportional to 521.55, 781.45 and 315.50

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Solution

The fourth proportional to 521.55, 781.45 and 315.50 is: 472.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    521.55 : 781.45 = 315.50 : x
  2. Step 2: Convert to fraction form
    521.55/781.45 = 315.50/x
  3. Step 3: Cross multiply
    521.55x = 781.45 × 315.50
  4. Step 4: Simplify right side
    521.55x = 246,542.78
  5. Step 5: Solve for x
    x = 246,542.78/521.55
  6. Step 6: Final answer
    x = 472.71

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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.