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Finding the Fourth Proportional to 380.43, 570.21 and 312.09

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Solution

The fourth proportional to 380.43, 570.21 and 312.09 is: 467.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    380.43 : 570.21 = 312.09 : x
  2. Step 2: Convert to fraction form
    380.43/570.21 = 312.09/x
  3. Step 3: Cross multiply
    380.43x = 570.21 × 312.09
  4. Step 4: Simplify right side
    380.43x = 177,956.84
  5. Step 5: Solve for x
    x = 177,956.84/380.43
  6. Step 6: Final answer
    x = 467.78

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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.