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Finding the Fourth Proportional to 386.31, 578.67 and 239.58

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Solution

The fourth proportional to 386.31, 578.67 and 239.58 is: 358.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.31 : 578.67 = 239.58 : x
  2. Step 2: Convert to fraction form
    386.31/578.67 = 239.58/x
  3. Step 3: Cross multiply
    386.31x = 578.67 × 239.58
  4. Step 4: Simplify right side
    386.31x = 138,637.76
  5. Step 5: Solve for x
    x = 138,637.76/386.31
  6. Step 6: Final answer
    x = 358.88

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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.