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Finding the Fourth Proportional to 687.73, 1,031.75 and 379.51

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Solution

The fourth proportional to 687.73, 1,031.75 and 379.51 is: 569.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.73 : 1,031.75 = 379.51 : x
  2. Step 2: Convert to fraction form
    687.73/1,031.75 = 379.51/x
  3. Step 3: Cross multiply
    687.73x = 1,031.75 × 379.51
  4. Step 4: Simplify right side
    687.73x = 391,558.52
  5. Step 5: Solve for x
    x = 391,558.52/687.73
  6. Step 6: Final answer
    x = 569.35

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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.