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Finding the Fourth Proportional to 485.15, 669.76 and 389.58

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Solution

The fourth proportional to 485.15, 669.76 and 389.58 is: 537.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.15 : 669.76 = 389.58 : x
  2. Step 2: Convert to fraction form
    485.15/669.76 = 389.58/x
  3. Step 3: Cross multiply
    485.15x = 669.76 × 389.58
  4. Step 4: Simplify right side
    485.15x = 260,923.15
  5. Step 5: Solve for x
    x = 260,923.15/485.15
  6. Step 6: Final answer
    x = 537.83

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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.