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Finding the Fourth Proportional to 659.60, 990.09 and 400.25

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Solution

The fourth proportional to 659.60, 990.09 and 400.25 is: 600.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.60 : 990.09 = 400.25 : x
  2. Step 2: Convert to fraction form
    659.60/990.09 = 400.25/x
  3. Step 3: Cross multiply
    659.60x = 990.09 × 400.25
  4. Step 4: Simplify right side
    659.60x = 396,283.52
  5. Step 5: Solve for x
    x = 396,283.52/659.60
  6. Step 6: Final answer
    x = 600.79

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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.