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Finding the Fourth Proportional to 485.60, 669.87 and 289.04

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Solution

The fourth proportional to 485.60, 669.87 and 289.04 is: 398.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.60 : 669.87 = 289.04 : x
  2. Step 2: Convert to fraction form
    485.60/669.87 = 289.04/x
  3. Step 3: Cross multiply
    485.60x = 669.87 × 289.04
  4. Step 4: Simplify right side
    485.60x = 193,615.88
  5. Step 5: Solve for x
    x = 193,615.88/485.60
  6. Step 6: Final answer
    x = 398.72

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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.