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Finding the Fourth Proportional to 927.70, 1,388.28 and 639.34

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Solution

The fourth proportional to 927.70, 1,388.28 and 639.34 is: 956.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    927.70 : 1,388.28 = 639.34 : x
  2. Step 2: Convert to fraction form
    927.70/1,388.28 = 639.34/x
  3. Step 3: Cross multiply
    927.70x = 1,388.28 × 639.34
  4. Step 4: Simplify right side
    927.70x = 887,582.94
  5. Step 5: Solve for x
    x = 887,582.94/927.70
  6. Step 6: Final answer
    x = 956.76

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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.