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Finding the Fourth Proportional to 663.20, 987.78 and 628.50

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Solution

The fourth proportional to 663.20, 987.78 and 628.50 is: 936.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    663.20 : 987.78 = 628.50 : x
  2. Step 2: Convert to fraction form
    663.20/987.78 = 628.50/x
  3. Step 3: Cross multiply
    663.20x = 987.78 × 628.50
  4. Step 4: Simplify right side
    663.20x = 620,819.73
  5. Step 5: Solve for x
    x = 620,819.73/663.20
  6. Step 6: Final answer
    x = 936.10

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.