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Finding the Fourth Proportional to 1,286.72, 1,929 and 636.56

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Solution

The fourth proportional to 1,286.72, 1,929 and 636.56 is: 954.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,286.72 : 1,929 = 636.56 : x
  2. Step 2: Convert to fraction form
    1,286.72/1,929 = 636.56/x
  3. Step 3: Cross multiply
    1,286.72x = 1,929 × 636.56
  4. Step 4: Simplify right side
    1,286.72x = 1,227,924.24
  5. Step 5: Solve for x
    x = 1,227,924.24/1,286.72
  6. Step 6: Final answer
    x = 954.31

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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.