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Finding the Fourth Proportional to 638.28, 957.78 and 345.78

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Solution

The fourth proportional to 638.28, 957.78 and 345.78 is: 518.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.28 : 957.78 = 345.78 : x
  2. Step 2: Convert to fraction form
    638.28/957.78 = 345.78/x
  3. Step 3: Cross multiply
    638.28x = 957.78 × 345.78
  4. Step 4: Simplify right side
    638.28x = 331,181.17
  5. Step 5: Solve for x
    x = 331,181.17/638.28
  6. Step 6: Final answer
    x = 518.87

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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.