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Finding the Fourth Proportional to 257.30, 387.75 and 231.65

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Solution

The fourth proportional to 257.30, 387.75 and 231.65 is: 349.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    257.30 : 387.75 = 231.65 : x
  2. Step 2: Convert to fraction form
    257.30/387.75 = 231.65/x
  3. Step 3: Cross multiply
    257.30x = 387.75 × 231.65
  4. Step 4: Simplify right side
    257.30x = 89,820.35
  5. Step 5: Solve for x
    x = 89,820.35/257.30
  6. Step 6: Final answer
    x = 349.09

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.