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Finding the Fourth Proportional to 659.20, 987.60 and 402.40

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Solution

The fourth proportional to 659.20, 987.60 and 402.40 is: 602.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.20 : 987.60 = 402.40 : x
  2. Step 2: Convert to fraction form
    659.20/987.60 = 402.40/x
  3. Step 3: Cross multiply
    659.20x = 987.60 × 402.40
  4. Step 4: Simplify right side
    659.20x = 397,410.24
  5. Step 5: Solve for x
    x = 397,410.24/659.20
  6. Step 6: Final answer
    x = 602.87

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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.