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Finding the Fourth Proportional to 391.80, 539.28 and 275.16

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Solution

The fourth proportional to 391.80, 539.28 and 275.16 is: 378.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.80 : 539.28 = 275.16 : x
  2. Step 2: Convert to fraction form
    391.80/539.28 = 275.16/x
  3. Step 3: Cross multiply
    391.80x = 539.28 × 275.16
  4. Step 4: Simplify right side
    391.80x = 148,388.28
  5. Step 5: Solve for x
    x = 148,388.28/391.80
  6. Step 6: Final answer
    x = 378.73

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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.