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Finding the Fourth Proportional to 472.80, 709.20 and 399.90

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Solution

The fourth proportional to 472.80, 709.20 and 399.90 is: 599.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    472.80 : 709.20 = 399.90 : x
  2. Step 2: Convert to fraction form
    472.80/709.20 = 399.90/x
  3. Step 3: Cross multiply
    472.80x = 709.20 × 399.90
  4. Step 4: Simplify right side
    472.80x = 283,609.08
  5. Step 5: Solve for x
    x = 283,609.08/472.80
  6. Step 6: Final answer
    x = 599.85

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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.