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Finding the Fourth Proportional to 689.17, 1,031.98 and 380.68

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Solution

The fourth proportional to 689.17, 1,031.98 and 380.68 is: 570.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.17 : 1,031.98 = 380.68 : x
  2. Step 2: Convert to fraction form
    689.17/1,031.98 = 380.68/x
  3. Step 3: Cross multiply
    689.17x = 1,031.98 × 380.68
  4. Step 4: Simplify right side
    689.17x = 392,847.08
  5. Step 5: Solve for x
    x = 392,847.08/689.17
  6. Step 6: Final answer
    x = 570.03

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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.