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Finding the Fourth Proportional to 381.20, 526.30 and 311.43

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Solution

The fourth proportional to 381.20, 526.30 and 311.43 is: 429.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    381.20 : 526.30 = 311.43 : x
  2. Step 2: Convert to fraction form
    381.20/526.30 = 311.43/x
  3. Step 3: Cross multiply
    381.20x = 526.30 × 311.43
  4. Step 4: Simplify right side
    381.20x = 163,905.60
  5. Step 5: Solve for x
    x = 163,905.60/381.20
  6. Step 6: Final answer
    x = 429.97

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.