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Finding the Fourth Proportional to 661.38, 992.06 and 389.20

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Solution

The fourth proportional to 661.38, 992.06 and 389.20 is: 583.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.38 : 992.06 = 389.20 : x
  2. Step 2: Convert to fraction form
    661.38/992.06 = 389.20/x
  3. Step 3: Cross multiply
    661.38x = 992.06 × 389.20
  4. Step 4: Simplify right side
    661.38x = 386,105.33
  5. Step 5: Solve for x
    x = 386,105.33/661.38
  6. Step 6: Final answer
    x = 583.79

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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.