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Finding the Fourth Proportional to 687.57, 1,031.33 and 379.58

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Solution

The fourth proportional to 687.57, 1,031.33 and 379.58 is: 569.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.57 : 1,031.33 = 379.58 : x
  2. Step 2: Convert to fraction form
    687.57/1,031.33 = 379.58/x
  3. Step 3: Cross multiply
    687.57x = 1,031.33 × 379.58
  4. Step 4: Simplify right side
    687.57x = 391,465.19
  5. Step 5: Solve for x
    x = 391,465.19/687.57
  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.