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Finding the Fourth Proportional to 686.04, 1,027.40 and 438.40

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Solution

The fourth proportional to 686.04, 1,027.40 and 438.40 is: 656.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.04 : 1,027.40 = 438.40 : x
  2. Step 2: Convert to fraction form
    686.04/1,027.40 = 438.40/x
  3. Step 3: Cross multiply
    686.04x = 1,027.40 × 438.40
  4. Step 4: Simplify right side
    686.04x = 450,412.16
  5. Step 5: Solve for x
    x = 450,412.16/686.04
  6. Step 6: Final answer
    x = 656.54

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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.