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Finding the Fourth Proportional to 426.41, 639.59 and 209.77

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Solution

The fourth proportional to 426.41, 639.59 and 209.77 is: 314.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.41 : 639.59 = 209.77 : x
  2. Step 2: Convert to fraction form
    426.41/639.59 = 209.77/x
  3. Step 3: Cross multiply
    426.41x = 639.59 × 209.77
  4. Step 4: Simplify right side
    426.41x = 134,166.79
  5. Step 5: Solve for x
    x = 134,166.79/426.41
  6. Step 6: Final answer
    x = 314.64

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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.