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Finding the Fourth Proportional to 391.47, 540.29 and 251.57

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Solution

The fourth proportional to 391.47, 540.29 and 251.57 is: 347.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.47 : 540.29 = 251.57 : x
  2. Step 2: Convert to fraction form
    391.47/540.29 = 251.57/x
  3. Step 3: Cross multiply
    391.47x = 540.29 × 251.57
  4. Step 4: Simplify right side
    391.47x = 135,921.32
  5. Step 5: Solve for x
    x = 135,921.32/391.47
  6. Step 6: Final answer
    x = 347.21

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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.