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Finding the Fourth Proportional to 671.01, 1,007.34 and 428.55

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Solution

The fourth proportional to 671.01, 1,007.34 and 428.55 is: 643.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    671.01 : 1,007.34 = 428.55 : x
  2. Step 2: Convert to fraction form
    671.01/1,007.34 = 428.55/x
  3. Step 3: Cross multiply
    671.01x = 1,007.34 × 428.55
  4. Step 4: Simplify right side
    671.01x = 431,695.56
  5. Step 5: Solve for x
    x = 431,695.56/671.01
  6. Step 6: Final answer
    x = 643.35

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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.