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Finding the Fourth Proportional to 391.29, 539.95 and 243.90

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Solution

The fourth proportional to 391.29, 539.95 and 243.90 is: 336.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.29 : 539.95 = 243.90 : x
  2. Step 2: Convert to fraction form
    391.29/539.95 = 243.90/x
  3. Step 3: Cross multiply
    391.29x = 539.95 × 243.90
  4. Step 4: Simplify right side
    391.29x = 131,693.81
  5. Step 5: Solve for x
    x = 131,693.81/391.29
  6. Step 6: Final answer
    x = 336.56

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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.