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Finding the Fourth Proportional to 687.28, 1,031.04 and 302.56

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Solution

The fourth proportional to 687.28, 1,031.04 and 302.56 is: 453.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.28 : 1,031.04 = 302.56 : x
  2. Step 2: Convert to fraction form
    687.28/1,031.04 = 302.56/x
  3. Step 3: Cross multiply
    687.28x = 1,031.04 × 302.56
  4. Step 4: Simplify right side
    687.28x = 311,951.46
  5. Step 5: Solve for x
    x = 311,951.46/687.28
  6. Step 6: Final answer
    x = 453.89

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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.