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Finding the Fourth Proportional to 659.20, 909.64 and 397.20

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Solution

The fourth proportional to 659.20, 909.64 and 397.20 is: 548.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.20 : 909.64 = 397.20 : x
  2. Step 2: Convert to fraction form
    659.20/909.64 = 397.20/x
  3. Step 3: Cross multiply
    659.20x = 909.64 × 397.20
  4. Step 4: Simplify right side
    659.20x = 361,309.01
  5. Step 5: Solve for x
    x = 361,309.01/659.20
  6. Step 6: Final answer
    x = 548.10

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.