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Finding the Fourth Proportional to 659.60, 989.40 and 400.40

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Solution

The fourth proportional to 659.60, 989.40 and 400.40 is: 600.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.60 : 989.40 = 400.40 : x
  2. Step 2: Convert to fraction form
    659.60/989.40 = 400.40/x
  3. Step 3: Cross multiply
    659.60x = 989.40 × 400.40
  4. Step 4: Simplify right side
    659.60x = 396,155.76
  5. Step 5: Solve for x
    x = 396,155.76/659.60
  6. Step 6: Final answer
    x = 600.60

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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.