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Finding the Fourth Proportional to 871.34, 1,202.39 and 478.40

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Solution

The fourth proportional to 871.34, 1,202.39 and 478.40 is: 660.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    871.34 : 1,202.39 = 478.40 : x
  2. Step 2: Convert to fraction form
    871.34/1,202.39 = 478.40/x
  3. Step 3: Cross multiply
    871.34x = 1,202.39 × 478.40
  4. Step 4: Simplify right side
    871.34x = 575,214.97
  5. Step 5: Solve for x
    x = 575,214.97/871.34
  6. Step 6: Final answer
    x = 660.15

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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.