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Finding the Fourth Proportional to 287.28, 396.72 and 209.88

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Solution

The fourth proportional to 287.28, 396.72 and 209.88 is: 289.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.28 : 396.72 = 209.88 : x
  2. Step 2: Convert to fraction form
    287.28/396.72 = 209.88/x
  3. Step 3: Cross multiply
    287.28x = 396.72 × 209.88
  4. Step 4: Simplify right side
    287.28x = 83,263.59
  5. Step 5: Solve for x
    x = 83,263.59/287.28
  6. Step 6: Final answer
    x = 289.83

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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.