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Finding the Fourth Proportional to 426.80, 640.31 and 207.50

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Solution

The fourth proportional to 426.80, 640.31 and 207.50 is: 311.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.80 : 640.31 = 207.50 : x
  2. Step 2: Convert to fraction form
    426.80/640.31 = 207.50/x
  3. Step 3: Cross multiply
    426.80x = 640.31 × 207.50
  4. Step 4: Simplify right side
    426.80x = 132,860.09
  5. Step 5: Solve for x
    x = 132,860.09/426.80
  6. Step 6: Final answer
    x = 311.29

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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.