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Finding the Fourth Proportional to 412.70, 617.70 and 320.90

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Solution

The fourth proportional to 412.70, 617.70 and 320.90 is: 480.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    412.70 : 617.70 = 320.90 : x
  2. Step 2: Convert to fraction form
    412.70/617.70 = 320.90/x
  3. Step 3: Cross multiply
    412.70x = 617.70 × 320.90
  4. Step 4: Simplify right side
    412.70x = 198,219.93
  5. Step 5: Solve for x
    x = 198,219.93/412.70
  6. Step 6: Final answer
    x = 480.30

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.