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Finding the Fourth Proportional to 551.20, 826.80 and 407.20

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Solution

The fourth proportional to 551.20, 826.80 and 407.20 is: 610.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    551.20 : 826.80 = 407.20 : x
  2. Step 2: Convert to fraction form
    551.20/826.80 = 407.20/x
  3. Step 3: Cross multiply
    551.20x = 826.80 × 407.20
  4. Step 4: Simplify right side
    551.20x = 336,672.96
  5. Step 5: Solve for x
    x = 336,672.96/551.20
  6. Step 6: Final answer
    x = 610.80

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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.