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Finding the Fourth Proportional to 485.60, 670.13 and 289.12

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Solution

The fourth proportional to 485.60, 670.13 and 289.12 is: 398.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    485.60 : 670.13 = 289.12 : x
  2. Step 2: Convert to fraction form
    485.60/670.13 = 289.12/x
  3. Step 3: Cross multiply
    485.60x = 670.13 × 289.12
  4. Step 4: Simplify right side
    485.60x = 193,747.99
  5. Step 5: Solve for x
    x = 193,747.99/485.60
  6. Step 6: Final answer
    x = 398.99

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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.