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Finding the Fourth Proportional to 391.05, 539.64 and 243.72

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Solution

The fourth proportional to 391.05, 539.64 and 243.72 is: 336.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.05 : 539.64 = 243.72 : x
  2. Step 2: Convert to fraction form
    391.05/539.64 = 243.72/x
  3. Step 3: Cross multiply
    391.05x = 539.64 × 243.72
  4. Step 4: Simplify right side
    391.05x = 131,521.06
  5. Step 5: Solve for x
    x = 131,521.06/391.05
  6. Step 6: Final answer
    x = 336.33

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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.