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Finding the Fourth Proportional to 659.38, 987.42 and 415.12

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Solution

The fourth proportional to 659.38, 987.42 and 415.12 is: 621.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.38 : 987.42 = 415.12 : x
  2. Step 2: Convert to fraction form
    659.38/987.42 = 415.12/x
  3. Step 3: Cross multiply
    659.38x = 987.42 × 415.12
  4. Step 4: Simplify right side
    659.38x = 409,897.79
  5. Step 5: Solve for x
    x = 409,897.79/659.38
  6. Step 6: Final answer
    x = 621.64

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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.