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Finding the Fourth Proportional to 671.21, 1,007.10 and 378.75

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Solution

The fourth proportional to 671.21, 1,007.10 and 378.75 is: 568.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    671.21 : 1,007.10 = 378.75 : x
  2. Step 2: Convert to fraction form
    671.21/1,007.10 = 378.75/x
  3. Step 3: Cross multiply
    671.21x = 1,007.10 × 378.75
  4. Step 4: Simplify right side
    671.21x = 381,434.71
  5. Step 5: Solve for x
    x = 381,434.71/671.21
  6. Step 6: Final answer
    x = 568.28

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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.