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Finding the Fourth Proportional to 668.20, 1,000.68 and 378.40

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Solution

The fourth proportional to 668.20, 1,000.68 and 378.40 is: 566.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    668.20 : 1,000.68 = 378.40 : x
  2. Step 2: Convert to fraction form
    668.20/1,000.68 = 378.40/x
  3. Step 3: Cross multiply
    668.20x = 1,000.68 × 378.40
  4. Step 4: Simplify right side
    668.20x = 378,657.31
  5. Step 5: Solve for x
    x = 378,657.31/668.20
  6. Step 6: Final answer
    x = 566.68

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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.