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Finding the Fourth Proportional to 871.10, 1,202.10 and 521.90

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Solution

The fourth proportional to 871.10, 1,202.10 and 521.90 is: 720.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    871.10 : 1,202.10 = 521.90 : x
  2. Step 2: Convert to fraction form
    871.10/1,202.10 = 521.90/x
  3. Step 3: Cross multiply
    871.10x = 1,202.10 × 521.90
  4. Step 4: Simplify right side
    871.10x = 627,375.99
  5. Step 5: Solve for x
    x = 627,375.99/871.10
  6. Step 6: Final answer
    x = 720.21

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.