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Finding the Fourth Proportional to 638.45, 959.70 and 457.10

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Solution

The fourth proportional to 638.45, 959.70 and 457.10 is: 687.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.45 : 959.70 = 457.10 : x
  2. Step 2: Convert to fraction form
    638.45/959.70 = 457.10/x
  3. Step 3: Cross multiply
    638.45x = 959.70 × 457.10
  4. Step 4: Simplify right side
    638.45x = 438,678.87
  5. Step 5: Solve for x
    x = 438,678.87/638.45
  6. Step 6: Final answer
    x = 687.10

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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.