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Finding the Fourth Proportional to 393.28, 542.76 and 304.90

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Solution

The fourth proportional to 393.28, 542.76 and 304.90 is: 420.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    393.28 : 542.76 = 304.90 : x
  2. Step 2: Convert to fraction form
    393.28/542.76 = 304.90/x
  3. Step 3: Cross multiply
    393.28x = 542.76 × 304.90
  4. Step 4: Simplify right side
    393.28x = 165,487.52
  5. Step 5: Solve for x
    x = 165,487.52/393.28
  6. Step 6: Final answer
    x = 420.79

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.