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Finding the Fourth Proportional to 485.20, 669.54 and 298.70

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Solution

The fourth proportional to 485.20, 669.54 and 298.70 is: 412.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.20 : 669.54 = 298.70 : x
  2. Step 2: Convert to fraction form
    485.20/669.54 = 298.70/x
  3. Step 3: Cross multiply
    485.20x = 669.54 × 298.70
  4. Step 4: Simplify right side
    485.20x = 199,991.88
  5. Step 5: Solve for x
    x = 199,991.88/485.20
  6. Step 6: Final answer
    x = 412.18

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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.