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Finding the Fourth Proportional to 871.20, 1,202.23 and 478.21

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Solution

The fourth proportional to 871.20, 1,202.23 and 478.21 is: 659.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    871.20 : 1,202.23 = 478.21 : x
  2. Step 2: Convert to fraction form
    871.20/1,202.23 = 478.21/x
  3. Step 3: Cross multiply
    871.20x = 1,202.23 × 478.21
  4. Step 4: Simplify right side
    871.20x = 574,918.41
  5. Step 5: Solve for x
    x = 574,918.41/871.20
  6. Step 6: Final answer
    x = 659.92

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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.