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Finding the Fourth Proportional to 871.20, 1,306.80 and 506.40

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Solution

The fourth proportional to 871.20, 1,306.80 and 506.40 is: 759.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    871.20 : 1,306.80 = 506.40 : x
  2. Step 2: Convert to fraction form
    871.20/1,306.80 = 506.40/x
  3. Step 3: Cross multiply
    871.20x = 1,306.80 × 506.40
  4. Step 4: Simplify right side
    871.20x = 661,763.52
  5. Step 5: Solve for x
    x = 661,763.52/871.20
  6. Step 6: Final answer
    x = 759.60

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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.