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Finding the Fourth Proportional to 687.82, 1,031.71 and 219.29

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Solution

The fourth proportional to 687.82, 1,031.71 and 219.29 is: 328.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.82 : 1,031.71 = 219.29 : x
  2. Step 2: Convert to fraction form
    687.82/1,031.71 = 219.29/x
  3. Step 3: Cross multiply
    687.82x = 1,031.71 × 219.29
  4. Step 4: Simplify right side
    687.82x = 226,243.69
  5. Step 5: Solve for x
    x = 226,243.69/687.82
  6. Step 6: Final answer
    x = 328.93

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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.