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Finding the Fourth Proportional to 426.80, 639.30 and 354.80

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Solution

The fourth proportional to 426.80, 639.30 and 354.80 is: 531.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.80 : 639.30 = 354.80 : x
  2. Step 2: Convert to fraction form
    426.80/639.30 = 354.80/x
  3. Step 3: Cross multiply
    426.80x = 639.30 × 354.80
  4. Step 4: Simplify right side
    426.80x = 226,823.64
  5. Step 5: Solve for x
    x = 226,823.64/426.80
  6. Step 6: Final answer
    x = 531.45

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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.