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Finding the Fourth Proportional to 426.96, 639.80 and 340.20

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Solution

The fourth proportional to 426.96, 639.80 and 340.20 is: 509.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.96 : 639.80 = 340.20 : x
  2. Step 2: Convert to fraction form
    426.96/639.80 = 340.20/x
  3. Step 3: Cross multiply
    426.96x = 639.80 × 340.20
  4. Step 4: Simplify right side
    426.96x = 217,659.96
  5. Step 5: Solve for x
    x = 217,659.96/426.96
  6. Step 6: Final answer
    x = 509.79

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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.