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Finding the Fourth Proportional to 638.75, 959.91 and 378.87

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Solution

The fourth proportional to 638.75, 959.91 and 378.87 is: 569.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.75 : 959.91 = 378.87 : x
  2. Step 2: Convert to fraction form
    638.75/959.91 = 378.87/x
  3. Step 3: Cross multiply
    638.75x = 959.91 × 378.87
  4. Step 4: Simplify right side
    638.75x = 363,681.10
  5. Step 5: Solve for x
    x = 363,681.10/638.75
  6. Step 6: Final answer
    x = 569.37

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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.