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Finding the Fourth Proportional to 289.92, 399.72 and 206.88

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Solution

The fourth proportional to 289.92, 399.72 and 206.88 is: 285.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.92 : 399.72 = 206.88 : x
  2. Step 2: Convert to fraction form
    289.92/399.72 = 206.88/x
  3. Step 3: Cross multiply
    289.92x = 399.72 × 206.88
  4. Step 4: Simplify right side
    289.92x = 82,694.07
  5. Step 5: Solve for x
    x = 82,694.07/289.92
  6. Step 6: Final answer
    x = 285.23

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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.