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Finding the Fourth Proportional to 638.72, 957.76 and 205.76

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Solution

The fourth proportional to 638.72, 957.76 and 205.76 is: 308.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.72 : 957.76 = 205.76 : x
  2. Step 2: Convert to fraction form
    638.72/957.76 = 205.76/x
  3. Step 3: Cross multiply
    638.72x = 957.76 × 205.76
  4. Step 4: Simplify right side
    638.72x = 197,068.70
  5. Step 5: Solve for x
    x = 197,068.70/638.72
  6. Step 6: Final answer
    x = 308.54

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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.