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Finding the Fourth Proportional to 440.20, 660.30 and 391.60

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Solution

The fourth proportional to 440.20, 660.30 and 391.60 is: 587.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    440.20 : 660.30 = 391.60 : x
  2. Step 2: Convert to fraction form
    440.20/660.30 = 391.60/x
  3. Step 3: Cross multiply
    440.20x = 660.30 × 391.60
  4. Step 4: Simplify right side
    440.20x = 258,573.48
  5. Step 5: Solve for x
    x = 258,573.48/440.20
  6. Step 6: Final answer
    x = 587.40

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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.