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Finding the Fourth Proportional to 426.09, 639.33 and 209.64

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Solution

The fourth proportional to 426.09, 639.33 and 209.64 is: 314.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.09 : 639.33 = 209.64 : x
  2. Step 2: Convert to fraction form
    426.09/639.33 = 209.64/x
  3. Step 3: Cross multiply
    426.09x = 639.33 × 209.64
  4. Step 4: Simplify right side
    426.09x = 134,029.14
  5. Step 5: Solve for x
    x = 134,029.14/426.09
  6. Step 6: Final answer
    x = 314.56

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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.