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Finding the Fourth Proportional to 426.16, 639.38 and 209.59

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Solution

The fourth proportional to 426.16, 639.38 and 209.59 is: 314.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.16 : 639.38 = 209.59 : x
  2. Step 2: Convert to fraction form
    426.16/639.38 = 209.59/x
  3. Step 3: Cross multiply
    426.16x = 639.38 × 209.59
  4. Step 4: Simplify right side
    426.16x = 134,005.40
  5. Step 5: Solve for x
    x = 134,005.40/426.16
  6. Step 6: Final answer
    x = 314.45

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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.