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Finding the Fourth Proportional to 1,425.29, 2,138.21 and 645.31

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Solution

The fourth proportional to 1,425.29, 2,138.21 and 645.31 is: 968.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,425.29 : 2,138.21 = 645.31 : x
  2. Step 2: Convert to fraction form
    1,425.29/2,138.21 = 645.31/x
  3. Step 3: Cross multiply
    1,425.29x = 2,138.21 × 645.31
  4. Step 4: Simplify right side
    1,425.29x = 1,379,808.30
  5. Step 5: Solve for x
    x = 1,379,808.30/1,425.29
  6. Step 6: Final answer
    x = 968.09

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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.