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Finding the Fourth Proportional to 426.90, 639.15 and 383.70

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Solution

The fourth proportional to 426.90, 639.15 and 383.70 is: 574.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.90 : 639.15 = 383.70 : x
  2. Step 2: Convert to fraction form
    426.90/639.15 = 383.70/x
  3. Step 3: Cross multiply
    426.90x = 639.15 × 383.70
  4. Step 4: Simplify right side
    426.90x = 245,241.86
  5. Step 5: Solve for x
    x = 245,241.86/426.90
  6. Step 6: Final answer
    x = 574.47

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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.