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Finding the Fourth Proportional to 319.28, 478.56 and 257.97

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Solution

The fourth proportional to 319.28, 478.56 and 257.97 is: 386.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    319.28 : 478.56 = 257.97 : x
  2. Step 2: Convert to fraction form
    319.28/478.56 = 257.97/x
  3. Step 3: Cross multiply
    319.28x = 478.56 × 257.97
  4. Step 4: Simplify right side
    319.28x = 123,454.12
  5. Step 5: Solve for x
    x = 123,454.12/319.28
  6. Step 6: Final answer
    x = 386.66

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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.