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Finding the Fourth Proportional to 515.60, 772.13 and 428.39

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Solution

The fourth proportional to 515.60, 772.13 and 428.39 is: 641.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    515.60 : 772.13 = 428.39 : x
  2. Step 2: Convert to fraction form
    515.60/772.13 = 428.39/x
  3. Step 3: Cross multiply
    515.60x = 772.13 × 428.39
  4. Step 4: Simplify right side
    515.60x = 330,768.91
  5. Step 5: Solve for x
    x = 330,768.91/515.60
  6. Step 6: Final answer
    x = 641.53

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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.