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Finding the Fourth Proportional to 687.15, 1,029.56 and 379.26

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Solution

The fourth proportional to 687.15, 1,029.56 and 379.26 is: 568.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.15 : 1,029.56 = 379.26 : x
  2. Step 2: Convert to fraction form
    687.15/1,029.56 = 379.26/x
  3. Step 3: Cross multiply
    687.15x = 1,029.56 × 379.26
  4. Step 4: Simplify right side
    687.15x = 390,469.03
  5. Step 5: Solve for x
    x = 390,469.03/687.15
  6. Step 6: Final answer
    x = 568.24

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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.