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Finding the Fourth Proportional to 3,286.50, 4,929.75 and 978

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Solution

The fourth proportional to 3,286.50, 4,929.75 and 978 is: 1,467

Step by Step Solution

  1. Step 1: Write the proportion equation
    3,286.50 : 4,929.75 = 978 : x
  2. Step 2: Convert to fraction form
    3,286.50/4,929.75 = 978/x
  3. Step 3: Cross multiply
    3,286.50x = 4,929.75 × 978
  4. Step 4: Simplify right side
    3,286.50x = 4,821,295.50
  5. Step 5: Solve for x
    x = 4,821,295.50/3,286.50
  6. Step 6: Final answer
    x = 1,467

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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.