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Finding the Fourth Proportional to 380.88, 570.66 and 257.21

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Solution

The fourth proportional to 380.88, 570.66 and 257.21 is: 385.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    380.88 : 570.66 = 257.21 : x
  2. Step 2: Convert to fraction form
    380.88/570.66 = 257.21/x
  3. Step 3: Cross multiply
    380.88x = 570.66 × 257.21
  4. Step 4: Simplify right side
    380.88x = 146,780.42
  5. Step 5: Solve for x
    x = 146,780.42/380.88
  6. Step 6: Final answer
    x = 385.37

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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.