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Finding the Fourth Proportional to 485.43, 669.90 and 289.02

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Solution

The fourth proportional to 485.43, 669.90 and 289.02 is: 398.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.43 : 669.90 = 289.02 : x
  2. Step 2: Convert to fraction form
    485.43/669.90 = 289.02/x
  3. Step 3: Cross multiply
    485.43x = 669.90 × 289.02
  4. Step 4: Simplify right side
    485.43x = 193,614.50
  5. Step 5: Solve for x
    x = 193,614.50/485.43
  6. Step 6: Final answer
    x = 398.85

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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.