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Finding the Fourth Proportional to 659.84, 987.38 and 398.90

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Solution

The fourth proportional to 659.84, 987.38 and 398.90 is: 596.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.84 : 987.38 = 398.90 : x
  2. Step 2: Convert to fraction form
    659.84/987.38 = 398.90/x
  3. Step 3: Cross multiply
    659.84x = 987.38 × 398.90
  4. Step 4: Simplify right side
    659.84x = 393,865.88
  5. Step 5: Solve for x
    x = 393,865.88/659.84
  6. Step 6: Final answer
    x = 596.91

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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.