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Finding the Fourth Proportional to 485.70, 668.97 and 392.28

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Solution

The fourth proportional to 485.70, 668.97 and 392.28 is: 540.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.70 : 668.97 = 392.28 : x
  2. Step 2: Convert to fraction form
    485.70/668.97 = 392.28/x
  3. Step 3: Cross multiply
    485.70x = 668.97 × 392.28
  4. Step 4: Simplify right side
    485.70x = 262,423.55
  5. Step 5: Solve for x
    x = 262,423.55/485.70
  6. Step 6: Final answer
    x = 540.30

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.