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Finding the Fourth Proportional to 520.80, 781.20 and 301.20

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Solution

The fourth proportional to 520.80, 781.20 and 301.20 is: 451.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.80 : 781.20 = 301.20 : x
  2. Step 2: Convert to fraction form
    520.80/781.20 = 301.20/x
  3. Step 3: Cross multiply
    520.80x = 781.20 × 301.20
  4. Step 4: Simplify right side
    520.80x = 235,297.44
  5. Step 5: Solve for x
    x = 235,297.44/520.80
  6. Step 6: Final answer
    x = 451.80

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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.