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Finding the Fourth Proportional to 426.30, 639.44 and 380.84

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Solution

The fourth proportional to 426.30, 639.44 and 380.84 is: 571.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.30 : 639.44 = 380.84 : x
  2. Step 2: Convert to fraction form
    426.30/639.44 = 380.84/x
  3. Step 3: Cross multiply
    426.30x = 639.44 × 380.84
  4. Step 4: Simplify right side
    426.30x = 243,519.23
  5. Step 5: Solve for x
    x = 243,519.23/426.30
  6. Step 6: Final answer
    x = 571.24

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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.